Crotch Depth Calculator — Trouser Rise

Sit on a hard flat chair. Measure from the waist (where you want the trouser waistband) straight down the side to the chair seat. This is your body crotch depth. Add ease for comfort.

Add 1.5-2.5cm ease for fitted trousers. Add 3-5cm for comfortable/relaxed fit. More ease gives a lower crotch point. Jeans typically have 2.5cm ease; palazzo trousers may have 5cm or more.

They refer to the same measurement: the distance from the waist to the crotch seam. Front rise is measured along the centre front; back rise along the centre back. Back rise is typically 5-10cm (2-4 inches) longer than front rise to accommodate the curve of the seat.

To lengthen: cut the pattern horizontally between waist and crotch curve, spread by the needed amount. To shorten: overlap the same amount. This adjusts rise without changing the leg length.