Cooking Time by Weight Calculator

About this calculator

Roasting time estimates from weight follow the pattern time = base time + (minutes per kilogram × weight), a rule of thumb cookbooks and roasting charts have long used because heat has to penetrate to the center of a joint of meat, and that penetration time scales roughly with mass (and therefore, for a similarly shaped roast, with weight) rather than with surface area alone. Minutes-per-kilogram figures differ by meat type, oven temperature, and target doneness, which is why they're published as ranges rather than a single universal number.

Home cooks and caterers use this kind of weight-based estimate to plan when to start a roast so it's ready at a specific serving time, especially for holiday centerpieces like turkey, ham, or prime rib where getting the timing wrong is costly. It's always treated as a starting estimate, refined with a meat thermometer, since oven calibration, bone-in versus boneless cuts, and starting temperature all shift the actual cooking time.