Fitness content is bilingual by accident: American programs talk pounds, European gyms plate in kilograms, and your app defaults to whichever its founders used. This guide makes you fluent in both, with the anchors lifters and runners actually need.
Body weight: the anchors
- The conversion: 1 kg = 2.20462 lb. Memorize "kg × 2.2" and you are within 1% always
- 60 kg = 132 lb, 75 kg = 165 lb, 90 kg = 198 lb, 100 kg = 220 lb
- Going the other way: lb ÷ 2.2. 180 lb = 82 kg, 150 lb = 68 kg
- Precision note: bathroom scales round; 79.9 kg vs 80.1 kg is the same body. Convert with the kg ↔ lb tool and stop recalculating daily
Gym plate math
Metric gyms: bar = 20 kg (men) / 15 kg (women). Plates: 25, 20, 15, 10, 5, 2.5, 1.25 kg.
American gyms: bar = 45 lb. Plates: 45, 35, 25, 10, 5, 2.5 lb.
| Total (incl. bar) | Metric plates/side | lb plates/side |
|---|---|---|
| 60 kg / 135 lb | 20 kg bar + 20/side | 45 lb bar + 45/side |
| 100 kg / 225 lb | + 40/side (20+20) | + 90/side (45+45) |
| 140 kg / 315 lb | + 60/side | + 135/side |
| 180 kg / 405 lb | + 80/side | + 180/side |
The milestone correspondence is not coincidence: 225 lb ≈ 102 kg (rounded to "two plates plus change"), 405 lb ≈ 184 kg ("four plates"). When translating a program, round to the nearest plate combo the gym actually has.
Running: pace, distance, weight classes
- 5K = 3.11 mi, 10K = 6.21 mi, half = 13.1 mi (21.1 km), marathon = 26.2 mi (42.2 km)
- Pace conversion: minutes per mile is 1.6x minutes per km. A 5:00/km runner runs 8:03/mi
- Treadmill mph ↔ pace: 6 mph = 10:00/mi = 6:15/km, 7.5 mph = 8:00/mi = 5:00/km, 9 mph = 6:40/mi = 4:10/km
BMI in either system
BMI = kg/m². With pounds and inches: BMI = 703 × lb / in². A 1.80 m, 80 kg person: 24.7 (upper normal range). The 703 constant exists purely so Americans need not convert first. BMI is a population screen, not a diagnosis; it ignores muscle mass entirely.
Other fitness units
- Calories burned: technically kcal, same as food labels
- Barbell/dumbbell weights abroad: metric plates on lb bars do not mix safely (collar sizes differ)
- Swimming: pools are 25 m (short course) or 50 m (Olympic); US yards pools are 25 yd = 22.86 m, making "20 laps" a different distance by country
- Boxing/weight classes: officially in kg, quoted in lb in the US. Middleweight: 72.5 kg / 160 lb
Convert right now