When Curtains Go on Sale in Japan (2026): How to Measure Right and Pick the Right Features

You can't judge curtain costs "per window" — know where the money leaks first

If you try to save on curtains by comparing price tags alone, your budget usually ends up growing later. The reason is simple: curtains rarely stop at "one panel per window." Most windows need two types, a drape (heavy curtain) and a sheer, and a two-panel window needs left and right panels of each. So a single floor-length window can need up to 4 panels. Count every window in your home and even a studio apartment often has 2–3, while a family home commonly has 5–8. Each price tag may look cheap, but the total can easily rival the cost of a piece of furniture.

And what pushes that total up the most isn't "choosing expensive fabric." It's measuring wrong and having to buy again. Too short and light leaks in, too long and it drags on the floor, too narrow and the edges gape — any of these means starting over, with return shipping for ready-made curtains or the full cost of remaking custom ones. So saving on curtains comes down to three things, before any discount hunting: "avoid wasteful rebuys," "choose just the right features for each window," and "since the total is large, buy everything together when rewards are high." This article focuses on the money flow of buying curtains, which stays relevant even as prices and specs change. Actual prices and sale details change over time, so always confirm on each online store's or manufacturer's official site.

What sets the price of curtains — area and tailoring, more than fancy fabric

Two "blackout curtains" can differ in price for reasons beyond brand name. Breaking down what drives the price shows you where to cut costs.

The key point: price is driven mainly by "area and number of panels," not "fabric grade." For example, splurging on high-performance fabric for a small waist-height bedroom window won't change the total much because the area is small. On the other hand, a large floor-length living room window has so much area that even a small difference in unit price adds up. Remember that "it's worth spending on large windows and features you can actually feel," and you can allocate your budget wisely.

The biggest saving is avoiding measuring mistakes — rebuying costs the most

The way people really throw money away on curtains isn't missing a discount but rebuying because of the wrong size. Fix this and you'll save more reliably than with any sale. The golden rule: measure from the curtain rail, not the window. Curtains hang on the rail, not the window.

• Width = rail length: Measure between the fixed runners (the loops that hold hooks) at both ends of the rail, not the window frame. As a guide, add a little extra so the pleats look nice.
• Length depends on window type: Floor-length windows hang just above the floor; waist-height windows a bit below the bottom of the frame. In both cases, measure from where the hooks hang.
• 1 window = 2 panels + sheers, up to 4: For two-panel windows, halve the rail width and buy two of the same. Count both drapes and sheers.
• "Remeasuring is a hassle" is the biggest trap: Ordering by eye ends up costing more in return shipping or remakes.

In particular, custom curtains generally can't be returned or exchanged. Since they're made to the centimeter, a size mistake is a total loss. Even with ready-made curtains, you often pay return shipping yourself for wrong sizes, and round-trip shipping isn't cheap. Just making one measurement sheet with the width, length and panel count for every window prevents this biggest expense. If you're not confident, use each store's measuring guides, videos or fabric samples.

Ready-made, custom or big-box stores — decide where to spend

There are three main ways to buy curtains: standard-size ready-made, size-specified custom, and furniture/big-box stores where you can see them in person. Their pricing works differently, so assigning each window to the right option keeps your total down.

There's one deciding question: are your measured width and length close to a standard ready-made size? Waist-height windows are typically around 135cm long, and floor-length windows 178cm or 200cm, so if you're close, choosing the nearest ready-made size is the best value. A little extra is absorbed by the pleats. If you send only non-standard windows — large, wide, bay windows or ones reaching near the ceiling — to custom, your total drops significantly compared with going custom for everything. Mixing like "custom only for the unusual bedroom window, ready-made for the rest" is the smart way to keep the total down.

The advantage of furniture and big-box stores (including their affiliated online shops) is that you can check the fabric's color, texture and thickness in person. That helps avoid rebuying because the color looked different on screen. In-store custom orders tend to be pricier, while their ready-made curtains and sets can be nearly as affordable as online. Check color and texture in a store or with samples, and compare prices and rewards by the online total — this two-pronged approach prevents both style mistakes and overpaying.

Not "everything included" but "the right feature for the right window" — what's worth paying for

Functional curtains are handy, but loading every window with every feature gets expensive fast. Features are worth paying for only when you'll actually notice the effect at that window. Choosing based on each window's problem lets you cut the total without losing satisfaction.

Of these, heat-blocking and insulating are the easiest to pay back over time. Windows are where the most heat enters and leaves a home, so putting heat-blocking or insulating curtains on large windows or in rooms with afternoon sun improves heating and cooling efficiency and saves on utilities. But the effect depends on how completely the curtains cover the window without gaps, so make the width and length a little larger than the window. On the other hand, splurging on high-end features for a small north-facing window gives poor value. Focusing your feature budget on "large windows with a clear problem" is the no-waste approach.

Living alone, shared family rooms, guest rooms — the right curtain depends on how you live

Even for the same "one waist-height window," what's worth paying for varies completely depending on how the people living there use the space. Since curtain prices are set by area and tailoring, getting priorities wrong easily leads to "paying for thickness where it doesn't help." Here we lay out five common situations, with which direction to go and which choices to avoid.

Living alone in a rental — decide by "does it face the street?" not the number of windows

Single-person apartments often have only 2–3 windows, and it's tempting to buy the same grade for all of them. But what really matters is one thing: which side faces a road or a neighbor's windows. Upgrading the sheers only on the side where people can see in, and using standard ready-made curtains for the rest, makes a noticeable difference for the same spending.

Especially on the ground floor or in rooms close to the building opposite, silhouettes show through sheers when your lights are on at night. Mirror sheers (with glossy threads woven into the outer side to block views during the day) work when outside light is strong, so think of it this way: at night the inside is brighter, and the effect reverses. If you spend a lot of time at home in the evening, the practical choice is privacy sheers that are hard to see through day and night, on street-facing windows only.

What to avoid is ordering custom sizes you can't take with you when you move out. Window heights vary from rental to rental, and the odds that the same length will work in your next place aren't high. If you might move within a few years, fitting your windows to standard ready-made lengths (the common sizes for waist-height and floor-length windows) tends to waste less in the end. A few extra centimeters of length can be taken up with adjustable hooks.

Shared family living room — how often it's opened and closed decides the fabric

Living room curtains are opened and closed many times a day. What matters here, more than the blackout grade, is stable pleats and hems that don't fray easily. The fabric rubs with every open and close, so thin, limp fabric starts to sag at the hem within about a year. For the drape (heavy curtain), choosing fabric with enough weight (thickness) for the pleats to stand up keeps it looking good longer.

Double fullness (2倍ヒダ — using fabric twice the window width to make pleats) looks great and has volume when gathered, but it uses more fabric and moves into a higher price range. It's worth it for the one main living room window, but doing double fullness throughout the house makes the total rise steeply. Double fullness only for the window you sit and look at, 1.5x fullness for the rest gives good results for the money.

Homes with small children or pets will find hems get dirtier than expected. If the fabric shrinks with every wash, a few washes can change how the hem sits relative to the rail. Even if the product page says "washable," being machine-washable and keeping its size after washing are two different things. 100% polyester is relatively stable in size, while blends with natural fibers tend to shrink. For windows you'll wash often, checking the fiber content label helps avoid regrets.

Bedroom — blackout depends on handling gaps more than on grade

People who find "the morning is so bright it wakes me up" sometimes buy Grade 1 blackout curtains and notice no difference. The reason is simple: light doesn't come through the fabric, it comes through gaps at the top, sides and bottom. In particular, the space between the rail and the wall (top) and the edges at both ends can't be fixed by fabric grade.

The fix isn't upgrading the fabric but changing how you size the width and length. Leave generous extra width beyond the window frame on both sides, and drop the length to just above the floor. For the top, if there's no curtain box, consider a return style (where the ends wrap back and attach to the wall) that covers the rail. For the same money, spending on sizing and fit makes the room darker than going up one blackout grade.

Conversely, if a bedroom window doesn't get strong afternoon sun and doesn't face the morning sun, top-grade blackout is overkill. A room with no daylight at all means turning on lights every time you fold laundry or change clothes. Avoid deciding mechanically that "it's a bedroom, so top grade" — check which direction the window gets light from in the morning before choosing a grade.

Rarely used rooms, storage rooms and small north-facing windows — sun protection over thickness

Windows in rooms you rarely use don't need heat-blocking or blackout. What matters here is two things: stopping furniture and floors from fading, and keeping the inside from being visible. It's common for a single UV-blocking sheer to be enough, and without a drape, a simple single-panel rail will do.

Small north-facing windows get almost no direct sunlight, so heat-blocking fabric does little there. Winter cold is the bigger issue, so leaning toward insulation (lined or thick fabric) matches what you'll actually feel. Heat-blocking and insulating are similar in "not letting heat through," but heat-blocking is designed to reflect sunlight, while insulation keeps indoor heat from escaping. Roughly assigning heat-blocking to south-to-west windows and insulation to north windows reduces waste.

Tight spaces or things in front of the window — decide length and opening style first

If a bed, desk or storage furniture sits below the window, floor-length curtains get in the way even on a floor-length window. In this case, cutting the length so it doesn't touch the furniture top makes opening and closing less annoying. If the hem rests on furniture, that spot rubs and discolors.

Also, for windows where you can only stand on one side (like a balcony door), a single panel can be more practical than two. A single panel covers the full width, so when opened, all the bulk gathers on one side. Before ordering, stand there and check which side of the window the stacking space (where the fabric bunches when open) would get in the way. Get this wrong and you'll be pushing through the curtain every time you go in and out.

When to buy curtains in 2026 — save by buying in bulk and comparing "real cost"

Because curtain purchases tend to involve many panels and a large total, buying everything together when discounts and point rewards overlap pays off. Here are the best timings specific to curtains.

• New-life season (February–April): Demand rises with moves, new school years and new jobs, and stores roll out curtain features and sets. It's a good time to replace curtains for every window at once, and easier to meet bulk-purchase shipping and point conditions.
• Seasonal changes: Before summer, heat-blocking and blackout features are common; before winter, insulation. It's easier to find the function you want. Targeting the features you need avoids waste.
• Big sales and fiscal year-end: Big shopping-mall sales and stores' fiscal year-end sales are when discounts and point rewards tend to stack. Since you buy multiple curtains, the larger total means bigger rewards.

Aim for the "real cost" rather than the listed price. If real cost = listed price − point rewards + shipping, buying drapes and sheers for several windows together to meet free shipping and point conditions in one go usually works out cheaper than buying one window at a time. Custom orders can take several weeks, so if you need them for a move, balance waiting for a sale with ordering early. Note that each mall's sale dates, point reward rates and campaign conditions may change, so don't assume — check the latest info on each official site.

Checks to avoid overpaying or choosing wrong when shopping online

Curtains are often bought online, where it's hard to check the real thing, and a miss means wasteful rebuying. Before you hit the order button, check these points on the product page and in reviews.

1. Match size and panel count against your measurement sheetAlways compare your measured width and length (from the rail) with the product dimensions. For two-panel windows, check the count too. This is the biggest saving point.
2. Check the blackout grade vs. "complete blackout"Look for grade labels like "Grade 1 blackout" (遮光1級). For bedrooms, check reviews for how dark it really gets.
3. Does it have only the features you need?Check the specs for heat-blocking, insulation, soundproofing, mirror/privacy, washable, shape memory and flame-retardant. Avoid overloading.
4. Expect color and texture to differ from the real thingColors on screen can look different in person. If the store offers samples, use them to avoid rebuying.
5. Are hooks and tiebacks included or sold separately?Check whether they come with the curtain. If sold separately, they add to your real cost.
6. Compare by real costLook at the total: listed price + shipping − point rewards. Buying multiple panels or sheers together to meet shipping conditions brings the price down.

The key to these checks is not chasing the lowest price item by item. Even if each panel is a bit cheaper, buying separately and paying extra shipping, or missing the size and rebuying, ruins it. List all your windows and choose a store by the total real cost — that's the shortest path to not overpaying for curtains.

Check in this order before you hit "order" — and what happens if you get it wrong

Curtain mistakes happen less from fabric choice and more from missed checks on size and specs. Once tailored, custom curtains often can't be returned, and even ready-made ones have exchange conditions once opened. Here's the order to check things while going back and forth between your actual rail and the product page. The order matters. Each step depends on the one before it, so go from the top without skipping.

1. Check the rail type firstFirst check whether it's a functional rail (angular, box-shaped, with runners sliding inside) or a decorative rail (a rod with rings). This changes the hook shape and where you start measuring the length. The most common mix-up is calculating the length assuming hooks on a decorative rail when it's actually a functional rail.
2. Fix the starting point for lengthFor a functional rail, start from the bottom of the runner's hole; for a decorative rail, from the bottom of the ring. If you measure from the top of the window frame or the top of the rail, curtains arrive several centimeters too long. On waist-height windows, too-long hems stick to the wall below the window; on floor-length windows, they pile up on the floor and collect dust.
3. Measure width from end to end of the railMeasure between the inner sides of the rail's fixed brackets, not the window frame. Measuring from the frame leaves you short by however far the rail extends beyond the window, and light leaks in from both sides when closed. In a bedroom, this makes the room bright regardless of blackout grade.
4. Check whether extra fullness is includedBoth ready-made and custom curtains are often made a few percent wider than the rail. Read the product page carefully to see whether "order size = finished size" or "extra is added to the order size." Adding it twice leaves excess fabric and baggy pleats; not adding it makes the curtains pull tight when fully closed.
5. Decide two-panel or single-panel, and which side the stack goesFor two panels, each panel's width is half the total plus overlap. Mixing up "is the order width for one panel or both combined?" means curtains arrive twice or half the width. The relationship between quantity and width labels is the most commonly misread part of product pages.
6. Hook type and adjustersA hooks (rail visible) and B hooks (rail hidden) change the look and light leakage even at the same length. Adjustable hooks let you tweak a few centimeters later, but the range is limited. If you measure carelessly thinking "I'll adjust when it arrives," you can exceed the range and be stuck.
7. Read what the blackout/heat-blocking labels really meanCurtains labeled just "blackout" (遮光) are different from those with a stated grade. Also, coated-back types block light well but tend to keep fold creases and may have limited washing options. Don't judge by the label alone; check the care label too.
8. Care label, shrinkage and flame-retardant statusEven washable curtains usually come with conditions like no tumble drying or laundry net required. In places where flame-retardant products are legally required, such as high-rise residences, you need the flame-retardant label (防炎ラベル). Check your building's management rules to see whether this applies.
9. Imagine the color "with the window behind it"From inside the room, curtains are always backlit. Flat-lay product photos are taken with front lighting, so the real thing looks a shade darker and less saturated. That's why a light color you chose can look deeper. If the store offers fabric samples, holding one up at the window is the surest check.
10. Check delivery time and return conditions lastCustom curtains take days to make. Check whether they'll arrive in time for your move or guests, and assume longer waits in busy periods (new-life season). Also read before ordering whether wrong-size returns are allowed and who pays shipping.

3 places where measurements often go wrong

Even following the steps above, measurements tend to go off in certain spots. These 3 are especially worth remeasuring.

• The rail is higher on one side — In older homes or with rails added later, the rail may not be level. If left and right differ, match the shorter side so the hem doesn't rub the floor. Matching the longer side leaves one side piling up on the floor.
• The floor height varies — Floor-length windows have sash tracks or steps at the window. If the hem rests on the step, it lifts there and lets light in. The standard approach is to leave a few centimeters above the floor.
• Curtain box depth — If there's a curtain box, check that a double rail fits and the hooks don't hit the ceiling. Interference inside the box causes snagging with every open and close and can crack the runners.

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