Work out garment size grading instantly with clear inputs, formula shown and shareable results.
Grading adds a fixed increment per size, and because a bodice pattern is drafted as a quarter of the body, each pattern piece moves by a quarter of that increment. The quarter rule is why a 4 cm grade only shifts a pattern edge by 1 cm, and getting it wrong doubles or quadruples the intended step.
Size range
size k = base measurement + k x grade increment
Pattern movement
movement per pattern piece = grade increment / 4
size k = base measurement + k x grade increment. Grading adds a fixed increment per size, and because a bodice pattern is drafted as a quarter of the body, each pattern piece moves by a quarter of that increment.
The quarter rule is why a 4 cm grade only shifts a pattern edge by 1 cm, and getting it wrong doubles or quadruples the intended step.
Enter base size bust or chest, grade increment per size, sizes in the range. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.