Cooking Time Scaler

How Cooking Time Scales With Weight

Cooking time scales roughly linearly with weight for most roasts and whole cuts. A 10-lb roast at 325°F takes about twice as long as a 5-lb roast at the same temperature. But it's not perfectly linear. Larger cuts have more mass relative to surface area, so heat penetrates slower per pound.

The Basic Formula

Total Time = Weight (lbs) x Minutes Per Pound

Minutes per pound varies by meat type and desired doneness. Beef at rare is about 15 min/lb, medium is 20 min/lb. Pork runs 20-25 min/lb. Chicken is around 20 min/lb at 375°F.

When to Use This

You have a recipe that says "cook a 5-lb roast for 2 hours" but you bought a 7-lb roast. Scale the time proportionally: 7/5 x 120 minutes = 168 minutes (about 2 hours 48 minutes). Works for beef, pork, lamb, chicken, and turkey.

Why a Thermometer Matters More Than a Timer

Every oven runs differently. Your 350°F might be someone else's 335°F. Altitude, starting temperature of the meat (fridge-cold vs. room temp), and pan material all affect cooking time. Use the scaled time as a guide, but pull the meat when a probe thermometer reads your target internal temperature. For beef medium-rare that's 135°F, for pork it's 145°F, for chicken it's 165°F.

Common Mistakes

Not resting the meat after cooking. Internal temperature rises 5-10°F during rest. Pull it out slightly early.

Opening the oven door repeatedly to check. Each opening drops the temperature by 25-50°F and adds cooking time.

Scaling time for stuffed poultry the same way as unstuffed. Stuffed birds need about 15 extra minutes per pound because the stuffing insulates the cavity.