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?

Standard grading increments are approximately 4cm per size at bust, waist and hip for sizes 6–16. For sizes above 16, the increment increases to approximately 5cm per size, as body proportions change differently at larger sizes.

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

Sizes 6–16: approx. 4cm per size at bust, waist, hip
Sizes 16+: approx. 5cm per size (larger increments)
Each "size" is a 2-number increment (e.g., 12 to 14)

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.