sewcalcs.uk
Dart Manipulation Calculator
Calculate dart point positions and intake amounts for bodice darts.
How We Calculate This
Dart Angle
Angle = 2 x arctan(Half Intake / Dart Length)
Dart Leg Length
Leg = sqrt(Dart Length² + Half Intake²)
Pivot Method
Closing the original dart causes the new dart to open with the same intake amount. The bust point acts as the pivot centre.
Frequently Asked Questions
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Last updated: March 2026
All calculations are estimates. Always verify quantities before cutting or purchasing fabric.