Sewing Pattern Grading Calculator
Enter a base measurement in cm and how many sizes up or down you are going: each step scales it by 4 percent, so 90 cm two sizes up is 97.2 cm.
Nova medida (cm)
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How pattern grading works
Grading takes a base pattern and scales it up or down across sizes, keeping the proportions in line. As a rule of thumb, each adult size adds ~5 cm to key measurements (bust, waist, hip), while children's sizes move by about 3 cm per age. Brazilian ready-to-wear follows ABNT NBR 16933: P = 82 cm bust, M = 87 cm, G = 92 cm, GG = 97 cm (women's torso). For dresses and confection, the reference is the ABRAVEST tables. The formula is new = base + delta · sizes, where delta runs 4–5 cm/size for adults or ~3 cm/age for kids. Grade the armhole, neckline and sleeve cap together. Scale the bust on its own and the fit falls apart.
Applications
Print & sew workflows (estamparia/confecção), independent ateliers, freelance dressmakers (costureira PJ), made-to-measure pieces, and fashion e-commerce that needs to grow a single sample into a full size run (PP–GGG).
FAQ
Can I grade by just enlarging the whole pattern? No. Blowing it up uniformly throws off arm length, neckline and rise. Proper grading moves each grading point by its own measured delta.
Are 5 cm steps always right? For women's adult sizes, yes on bust and hip, though the waist often steps by 4 cm. Children move 3 cm per age, easing up to 4 cm once you hit teen sizes.
Which size chart should I use? Reach for ABNT NBR 16933 on general apparel, ABRAVEST for dresses and uniforms, and a brand's own tables when you're after a premium fit.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.