Weight Conversion Calculator

Mass is constant regardless of gravity, while weight varies with gravitational force. For practical Earth-based conversions, we treat them equivalently using standard gravity (9.8 m/s²). Our calculator provides precise conversions suitable for everyday use, cooking, and most scientific applications. For space or high-precision scientific work where gravity varies significantly, mass measurements (kilograms) should be used instead of weight measurements for accuracy.

Our calculator uses internationally recognized conversion factors with high precision: 1 kg = 2.20462262185 pounds, 1 pound = 0.45359237 kg, 1 ounce = 28.349523125 grams. These are based on NIST standards and international measurement protocols (BIPM, ISO) and provide accuracy suitable for scientific, commercial, pharmaceutical, and culinary applications. The precision exceeds typical kitchen scale accuracy by several orders of magnitude.

There are three main ton measurements: Metric ton (1000 kg), US ton/short ton (2000 lb ≈ 907.185 kg), and UK ton/long ton (2240 lb ≈ 1016.047 kg). The metric ton is used worldwide in science and international trade. US tons are common in American commerce, while UK tons are used in Britain and some Commonwealth countries. Always specify which ton you're using to avoid confusion in international contexts and commercial transactions.

Stones are commonly used for body weight in the UK and Ireland. One stone equals 14 pounds exactly. To convert stones to pounds, multiply by 14. To convert pounds to stones, divide by 14. For example: 10 stone = 140 lb, 154 lb = 11 stone. Our calculator handles these conversions automatically and can display results in combined format (e.g., 11 stone 4 lb) for traditional body weight measurements used in healthcare and fitness contexts.

For small weights (under 100 grams), use grams or ounces with precision digital scales. Milligrams are used for very small measurements like medication dosages. Digital kitchen scales typically measure to 1-gram precision, while laboratory scales can measure milligrams or micrograms. When converting small weights, our calculator maintains precision up to 6 decimal places to ensure accuracy for scientific, pharmaceutical, and precision cooking applications where exact measurements are critical.

Absolutely! Our calculator is perfect for cooking and baking conversions and is trusted by professional chefs and home cooks alike. For best results in recipes, use weight measurements (grams or ounces) rather than volume measurements (cups or spoons) for dry ingredients like flour, sugar, and spices. Weight measurements are more accurate, consistent, and reproducible. Many modern recipes provide weight equivalents for precision baking, and our converter ensures you get the exact measurements needed for perfect results every time.

While our calculator uses medically precise conversion factors and NIST-verified accuracy, for actual medical dosage calculations or pharmaceutical compounding, always consult healthcare professionals and use approved medical measurement devices. Our tool provides educational and reference precision suitable for understanding weight conversions in medical contexts, but critical healthcare decisions should always be verified through proper medical channels and equipment.