What is pattern grading?

Pattern grading is the process of proportionally increasing or decreasing a pattern to create different sizes. Each edge of the pattern moves by a calculated amount, maintaining the overall shape and proportions.

How much does each size change by?

On the standard Big-4 / Misses grade (Simplicity, Vogue, Butterick, McCall’s), the bust and hip step about 5 cm (2 inches) per size, while the waist steps a smaller 3.8 cm (1½ inches) per size. For example sizes 12/14/16 measure 34/36/38 inch bust, 26½/28/30 inch waist and 36/38/40 inch hip. At larger sizes the waist grade widens toward 5 cm (2 inches) to match the bust and hip.

Can I grade more than one size?

You can grade 1–2 sizes with reasonable accuracy. Beyond 2 sizes, proportions change significantly and it is better to use a pattern drafted for the target size range. Grading 3+ sizes can affect armhole shape, shoulder slope, and dart placement.

Is grading the same as resizing?

Grading moves all pattern edges proportionally. It is different from making a targeted adjustment (like a bust or hip adjustment) which changes only one area. Grading changes the entire pattern uniformly.

SewCalcs

Grading Calculator — Grade Patterns Between Sizes

Calculate grading increments to resize a sewing pattern up or down between sizes.

Current Pattern Size

The size your pattern is drafted for

Target Size

The size you want to grade to

How We Calculate This

Pattern grading uses standard increments per size step. Each measurement point on the pattern shifts by a calculated amount. The direction is automatically determined from your current and target sizes.

Standard increments (Big-4 / Misses)

Bust: ~5 cm (2") per size
Hip: ~5 cm (2") per size
Waist: ~3.8 cm (1½") per size — the waist grades a little less than bust and hip
At larger sizes the waist grade widens toward ~5 cm (2")
Each "size" is a 2-number increment (e.g., 12 to 14)

The total change is spread evenly around the body, so each quarter-pattern piece moves by about a quarter of the figures above.

Frequently Asked Questions

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Waist Adjustment Calculator

Adjust waist measurements on skirt and trouser patterns.

Last updated: February 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.