How to Calculate Border Yardage: A Complete Guide

Quick answer: how to calculate border yardage

Calculate one border at a time, innermost first. Finished size after a border equals current width plus 2 times border width, and current length plus 2 times border width. For a straight border, side strips equal current length, and top and bottom strips equal finished width. Total strip length equals 2 times side length plus 2 times top and bottom length. Strips are rounded up, and yardage for that border is exact yardage rounded up to the nearest 1/8 yard. Use the finished size from that border as the current size for the next border. Add the per-border buy yardages for the total, never add exact yardages and round only once at the end.

Example: a 50 by 60 inch top, Border 1 is 3 inches, Border 2 is 5 inches, both straight, usable fabric width 44 inches, seam 0.5 inch. Border 1 gives finished 56 by 66 inches, buy 0.75 yards. Border 2 gives finished 66 by 76 inches, buy 1.25 yards. Total to buy is 2.00 yards, for two different border fabrics.

Scope, stated plainly: the Border Yardage Calculator handles up to 3 borders in one run, with one corner type, straight or mitered, for the whole run. If you mix straight and mitered borders, calculate each method separately, with its own strip rule. If two borders share the same fabric, the per-border buy total is still safe, because each border is rounded up on its own, but it can be a little higher than a combined calculation.

If you only need a number, use the Border Yardage Calculator. If you want to understand why each border must be rounded on its own, read on.

What border yardage means

Border yardage is the amount of fabric you need to buy for borders, measured in yards or metres. It is not the same as border strip length. Strip length tells you how long each strip must be. Yardage tells you how much fabric to buy to cut those strips, after accounting for fabric width, strip joins and rounding up.

Border yardage is also different from total quilt yardage. Total quilt yardage includes blocks, sashing, borders, backing and binding. Border yardage is only the border part, so you can shop for each border fabric separately, without guessing at the fabric shop.

Why multiple borders need careful yardage

Multiple borders look simple, but their yardage is easy to get wrong, because each outer border is larger than the one inside it. The inner border is added to the quilt top. The next border is added to a larger size, the finished size after the first border. The third border is added to an even larger size.

If you add all border widths to the original top at once, and then cut all strips to that one size, outer border strips will be too short. The correct method is one border at a time, in order, from inner to outer. That is the method the Border Yardage Calculator uses.

Step by step: how to calculate border yardage

Step 1: Measure the quilt top

Measure the finished top, pressed flat, in two places for width and two places for length. Use the larger number for each. Square up the top first, because borders follow the edge they are sewn to.

Step 2: Calculate the first border

Finished width equals current width plus 2 times border width. Finished length equals current length plus 2 times border width. For straight borders, side strip length equals current length, and top and bottom strip length equals current width plus 2 times border width. For mitered borders, add 2 times border width plus 2 times seam allowance to each strip length, for the 45 degree corners.

Step 3: Work out strips and yardage for that border

Total strip length equals 2 times side strip length plus 2 times top and bottom strip length. If total length fits in one fabric width, you need 1 strip. If not, each extra strip adds fabric width minus seam allowance, because seam allowance is lost at each join. Strips are rounded up. Fabric length equals strips times cut width. Cut width equals finished border width plus seam allowance on both sides. Exact yardage equals fabric length divided by 36 in inch mode. Yardage to buy for that border equals exact yardage rounded up to the nearest 1/8 yard.

Step 4: Repeat for each outer border

Use the finished size from the border you just calculated as the top size for the next border. Repeat the same steps. Do not go back to the original top size.

Step 5: Add yardage per border for the total

Add yardage to buy per border together for total yardage to buy. Yardage is rounded up per border, because each border is usually a different fabric, bought separately. If all borders use the same fabric, the total will be slightly conservative, which is safer than coming up short.

Worked example: a lap quilt with two borders

Take a lap top that measures 50 by 60 inches. Add Border 1, 3 inches wide, then Border 2, 5 inches wide, both straight, with 44 inch fabric and 0.5 inch seam allowance.

Border 1: finished size 56 by 66 inches. Side strips 2 times 60 inches, top and bottom strips 2 times 56 inches, total 232 inches. Strips equal 1 plus the ceiling of (232 minus 44) divided by 43.5, which is 6 strips. Cut width is 3 plus 2 times 0.5, which is 4 inches. Fabric length 6 times 4 equals 24 inches. Exact yardage 24 divided by 36 equals 0.67 yards. Yardage to buy, rounded up to the nearest 1/8 yard, equals 0.75 yards.

Border 2: start from 56 by 66 inches, not from the original top. Finished size 66 by 76 inches. Side strips 2 times 66 inches, top and bottom strips 2 times 66 inches, total 264 inches. Strips equal 1 plus the ceiling of (264 minus 44) divided by 43.5, which is 7 strips. Cut width is 5 plus 2 times 0.5, which is 6 inches. Fabric length 7 times 6 equals 42 inches. Exact yardage 42 divided by 36 equals 1.17 yards. Yardage to buy, rounded up to the nearest 1/8 yard, equals 1.25 yards.

Total yardage to buy: 0.75 plus 1.25 equals 2.00 yards, for two different border fabrics.

With 108 inch fabric, Border 1 needs 3 strips, 12 inches of fabric, 0.38 yards to buy, and Border 2 needs 3 strips, 18 inches of fabric, 0.50 yards to buy, a total of 0.88 yards. Wide fabric uses fewer strips, but check price per yard, not only total yards.

Border yardage table, our own computed table

This table is the worked example above, in table form, so each border can be checked at a glance. It uses a 50 by 60 inch top, straight borders, usable fabric width 44 inches, and seam 0.5 inch, and it is computed from the same per-border rule as the calculator, not copied from another site.

Border	Border width	Finished size after border	Total strip length	Strips	Yardage to buy
Border 1, innermost	3 in	56 by 66 in	232 in	6	0.75 yards
Border 2, outermost	5 in	66 by 76 in	264 in	7	1.25 yards
Total, two different fabrics				13	2.00 yards

How to make sure your result is correct

• Running size check. Each border must start from the finished size of the previous border, not from the original top, or every outer border will be too short.
• Strip length check. For a straight border, side strips must equal current length, and top and bottom strips must equal finished width, including side borders.
• Per-border rounding check. Each border must be rounded up to 1/8 yard on its own, before adding. Adding exact yardages and rounding once can leave a border short by a few inches.
• Total check. Total buy yardage must equal the sum of the per-border buy yardages, not the buy yardage of the sum of exact yardages, when rounding differs.
• Usable width check. Enter usable fabric width after removing selvages, not bolt width, or strip count can be too low near a boundary.
• Corner type check. Straight and mitered borders use different strip lengths. Do not mix them in one run, or one border will be cut to the wrong length.

Shopping for border fabric

• Shop per border, not per quilt. Write down yardage per border, and buy each border fabric by its own number, especially if fabrics are different.
• Check fabric width, not just yardage. A fabric sold as 44 inches wide may give less usable width after trimming selvages. If usable width is smaller, enter the smaller width as custom fabric width in the calculator.
• Check print direction. A directional print may need extra fabric to keep the print running the right way around the quilt, especially for mitered borders. The calculator does not account for print matching, so buy extra for that job.
• Think about shrinkage. If you prewash the top, prewash border fabric in the same way, so layers shrink together. The calculator does not add shrinkage, so do not rely on rounding up to cover a large shrinkage difference.
• Keep a little safety margin in mind. The calculator already rounds yardage up per border. If you are new to borders, or cutting from a print you cannot replace, buying a little extra beyond the calculator result is a practical choice, but it is your choice, not part of the calculation.

Common mistakes that leave border fabric short

• Adding all border widths to the original top. Outer borders are larger than inner borders, so they need longer strips. Calculate one border at a time, in order.
• Forgetting seam allowance at joins. A joined strip loses seam allowance at each join, so usable length is less than fabric width times strips.
• Rounding only at the end, for different fabrics. If borders are different fabrics, each border must be rounded up separately, because you cannot use leftover fabric from one border fabric to finish another.
• Using nominal width as usable width. If usable width is less than nominal width, strip count will be too low, and yardage will come up short.
• Using straight lengths for mitered borders. Mitered strips need extra length for the 45 degree corners. Use the mitered method for mitered borders.

Frequently asked questions

Related guides and calculators

Next, read How to Calculate Border for straight borders, and How to Calculate Mitered Border for 45 degree corners. Use the Border Yardage Calculator for your own measurements, and see the Binding Calculator for the finished edge.