Methodology & formula sources
Transparency is the core of our E-E-A-T: this page documents every formula behind LiftPace's calculators and where it comes from. We do not use any private or live data feed — each tool implements a standard, published equation, and the math is also shown on the tool's own page.
Formula references
| Reference | Refresh cadence | Use / license |
|---|---|---|
| Mifflin-St Jeor equation (Mifflin et al., 1990, Am J Clin Nutr) | none | Published formula (reference use) |
| Harris-Benedict equation (Harris & Benedict 1919; Roza & Shizgal revision 1984) | none | Published formula (reference use) |
| Epley & Brzycki one-rep-max formulas (Epley 1985; Brzycki 1993) | none | Published formula (reference use) |
| Riegel race-time model (Riegel 1981, American Scientist) | none | Published formula (reference use) |
| U.S. Navy body-fat circumference method (Hodgdon & Beckett 1984) | none | Published formula (reference use) |
| 2011 Compendium of Physical Activities (MET values; Ainsworth et al.) | none | Reference values (cited) |
| Devine, Robinson & Miller ideal-body-weight formulas | none | Published formula (reference use) |
| Tanaka maximum heart-rate equation (Tanaka et al. 2001) & Karvonen reserve method | none | Published formula (reference use) |
Cadence is "none" for every reference: these are fixed published formulas, not data feeds, so there is nothing to refresh. We review the implementations periodically.
What each calculator uses
- TDEE & BMR — Mifflin-St Jeor (1990) BMR equation × an activity multiplier (1.2–1.9).
- Macros — protein set per body weight, fat as a % of calories, carbohydrate as the remainder (4/4/9 kcal per gram).
- Body fat — U.S. Navy circumference method (Hodgdon & Beckett, 1984).
- Ideal body weight — Devine (1974), Robinson (1983) and Miller (1983) equations, shown as a range.
- One-rep max — Epley (1985) and Brzycki (1993), with a standard %1RM–rep table.
- Running pace — pace = time ÷ distance, with unit conversion (1 mi = 1.609344 km).
- Race time predictor — Riegel (1981): T2 = T1 × (D2 ÷ D1)1.06.
- Calories burned — MET method: calories = MET × weight (kg) × hours, using the 2011 Compendium of Physical Activities.
- Water intake — ~35 ml per kg body weight plus ~12 ml per minute of exercise (general guideline).
- Heart-rate zones — max HR via 220−age and Tanaka (208 − 0.7 × age); zones via the Karvonen heart-rate-reserve method.
How calculations work
Every calculator runs entirely in your browser as a small vanilla-JavaScript island using the formulas above. We do not store, transmit or log your inputs — there is no account and no upload.
Limitations
Formula-based estimates are population averages and can differ from your real values by 10% or more. They are general fitness information, not medical, dietary or training advice for any individual. Always verify against your own results over time and consult a qualified professional before changing your diet or exercise. See our disclaimer.