Fitness Data & Formulas Reference
23 peer-reviewed formulas across 11 calculators. Download as JSON or CSV.
Formula Registry
This registry collects 23 peer-reviewed formulas used across 11 fitness calculators on this site. Each formula includes its original author, publication year, equation, and a direct link to the calculator that implements it.
Choose the formula that matches your available data. If you know your body fat percentage, Katch-McArdle gives a more accurate BMR than Mifflin-St Jeor. If you only have height and weight, start with Mifflin-St Jeor. Each calculator applies these formulas automatically — this page serves as the unified reference.
| Formula | Author(s) | Year | Category | Equation | Calculator |
|---|---|---|---|---|---|
| Mifflin-St Jeor | Mifflin & St Jeor | 1990 | BMR | 10×W + 6.25×H − 5×A ± s | TDEE / Calorie |
| Harris-Benedict (revised) | Harris & Benedict / Roza & Shizgal | 1919 / 1984 | BMR | 13.397W + 4.799H − 5.677A + 88.362 (♂) | Calorie |
| Katch-McArdle | Katch & McArdle | 1983 | BMR | 370 + 21.6 × LBM | TDEE / Calorie |
| Hodgdon-Beckett (US Navy) | Hodgdon & Beckett | 1984 | Body Fat % | 86.010×log₁₀(waist−neck) − 70.041×log₁₀(height) + 36.76 (♂) | Body Fat |
| FFMI | Kouri et al. | 1995 | Fat-Free Mass Index | LBM(kg) / height(m)² + 6.1×(1.8 − height) | FFMI |
| BMI (Quetelet) | Quetelet | 1832 | Body Mass Index | weight(kg) / height(m)² | BMI |
| Boer | Boer | 1984 | Lean Body Mass | 0.407×W + 0.267×H − 19.2 (♂) | LBM |
| James | James | 1976 | Lean Body Mass | 1.1×W − 128×(W/H)² (♂) | LBM |
| Hume | Hume | 1966 | Lean Body Mass | 0.32810×W + 0.33929×H − 29.5336 (♂) | LBM |
| Devine | Devine | 1974 | Ideal Weight | 50 + 2.3×(inches over 5′) (♂) | Ideal Weight |
| Hamwi | Hamwi | 1964 | Ideal Weight | 48 + 2.7×(inches over 5′) (♂) | Ideal Weight |
| Robinson | Robinson | 1983 | Ideal Weight | 52 + 1.9×(inches over 5′) (♂) | Ideal Weight |
| Miller | Miller | 1983 | Ideal Weight | 56.2 + 1.41×(inches over 5′) (♂) | Ideal Weight |
| Epley | Epley | 1985 | 1RM | W × (1 + r/30) | 1RM |
| Brzycki | Brzycki | 1993 | 1RM | W × 36 / (37 − r) | 1RM |
| Lander | Lander | 1985 | 1RM | 100×W / (101.3 − 2.67123×r) | 1RM |
| Lombardi | Lombardi | 1989 | 1RM | W × r0.10 | 1RM |
| Mayhew | Mayhew et al. | 1992 | 1RM | 100×W / (52.2 + 41.9×e−0.055×r) | 1RM |
| O’Conner | O’Conner et al. | 1989 | 1RM | W × (1 + r/40) | 1RM |
| Wathan | Wathan | 1994 | 1RM | 100×W / (48.8 + 53.8×e−0.075×r) | 1RM |
| Wilks Polynomial | Wilks | ~1989 | Strength Score | Total × 600 / [a + b(BW) + c(BW²) + d(BW³) + e(BW⁴) + f(BW⁵)] | Wilks |
| Karvonen | Karvonen | ~1957 | Heart Rate Zones | ((MaxHR − RestHR) × %Intensity) + RestHR | HR Zones |
| VO2 Max (Uth et al.) | Uth et al. | 2004 | VO2 Max | 15.3 × (MaxHR / RestingHR) | VO2 Max |
Frequently Asked Questions
How many calories should I eat to lose weight?
Calculate your TDEE and subtract 300-500 calories per day for a sustainable deficit of ~0.5 kg/week fat loss. Read more →
What is TDEE and how is it calculated?
TDEE = BMR × activity multiplier. Use Mifflin-St Jeor (1990) for BMR, then multiply by 1.2-1.9 based on activity level. Calculate yours →
How fast can you realistically lose fat?
0.5-1% of bodyweight per week is sustainable. Faster rates increase muscle loss and metabolic adaptation. Read more →
What is a caloric deficit?
Consuming fewer calories than your body burns (TDEE). A 500 cal/day deficit produces ~0.45 kg/week fat loss. Read more →
What is body recomposition?
Losing fat and gaining muscle simultaneously. Most effective for beginners, detrained individuals, or those with higher body fat. Read more →
Is fasted cardio more effective for fat loss?
No. Total daily caloric deficit determines fat loss, not meal timing. Fasted cardio shows no advantage for total fat loss over 24 hours. Read more →
Which BMR formula should I use — Mifflin-St Jeor or Katch-McArdle?
Use Mifflin-St Jeor as default. Use Katch-McArdle if you know your body fat percentage — it accounts for lean mass and is more accurate for muscular or lean individuals. TDEE Calculator →
How are BMR, TDEE, and body fat percentage related?
BMR is your resting calorie burn. TDEE = BMR × activity multiplier. Body fat percentage determines lean mass, which the Katch-McArdle formula uses for a more accurate BMR. TDEE Calculator →
What is the most accurate 1RM formula?
Epley and Brzycki are most accurate for 1-10 rep ranges. For higher reps (10+), Wathan and Mayhew track better. Averaging all 7 formulas reduces individual formula error. 1RM Calculator →
How do I use my body fat to calculate a more accurate TDEE?
Measure body fat with the Navy method, calculate lean body mass, then use Katch-McArdle (370 + 21.6 × LBM) instead of Mifflin-St Jeor. This eliminates the gender variable. Body Fat Calculator →
What is the difference between BMI and body fat percentage?
BMI uses only height and weight — it cannot distinguish muscle from fat. Body fat percentage measures actual fat mass. A muscular person can have an “overweight” BMI with a healthy body fat percentage. BMI Calculator →
Which ideal weight formula is most accurate?
No single formula fits everyone. Robinson (1983) and Miller (1983) give more realistic targets for modern populations than the older Devine (1974) formula. All four are population averages, not individual prescriptions. Ideal Weight Calculator →