Strength, Running & Nutrition Calculators
Free, no-signup fitness calculators. Every tool shows its formula, a worked example you can verify by hand, and honest limitations — no black boxes.
Strength — 1RM & Training
One-rep-max estimates from three rep-based formulas, plate loading, and percentage charts for programming.
One Rep Max Calculator
Estimate 1RM with Epley, Brzycki and Lombardi, compare the three results, and view this site’s arithmetic mean.
Bench Press 1RM Calculator
Bench press 1RM calculator with barbell plate loading: estimate your max from a rep set, then see which plates
Squat 1RM Calculator
Squat one rep max calculator: turn any working set into an estimated 1RM with Epley, Brzycki and Lombardi form
Deadlift 1RM Calculator
Estimate a deadlift 1RM from a rep set, compare three equations, and view per-side plate loading and percentage weights.
1RM Percentage Chart
Interactive one rep max percentage chart: enter your 1RM for a full training table from 100% to 50%, with rep
Running — Pace & Race
Pace calculators, converters and race prediction from 5K to marathon.
Running Pace Calculator
Free running pace calculator: enter distance and time to get your pace in min/km and min/mile, plus speed in k
Marathon Pace Calculator
Marathon pace calculator: enter your goal finish time to get the exact required pace per km and mile, plus a 5
5K Pace Calculator
5K pace calculator: get your current pace and Riegel-based predictions for 10K, half marathon and marathon fro
Half Marathon Pace Chart
Half marathon pace chart: pick a goal finish time to see required pace per km/mile and mile splits. Covers 1:3
Pace Converter
Running pace converter: instantly convert between min/km, min/mile, mph and kph. One input, all four units, wi
Nutrition — Calories & Protein
Resting-energy estimates from Mifflin-St Jeor, with site-selected activity factors, calorie adjustments and protein planning presets.
TDEE Calculator
Free TDEE calculator using the Mifflin-St Jeor equation: enter sex, weight, height, age and activity level for
Bulking Calorie Calculator
Bulking calorie calculator: start from your TDEE and add a lean 10–20% surplus for muscle gain, with protein t
Cutting Calorie Calculator
Cutting calorie calculator: build a 15–25% deficit from your TDEE for fat loss while keeping muscle, with mini
Protein Intake Calculator
Protein intake calculator: daily protein grams from body weight using the ISSN position stand range of 1.6–2.2
Why TrainMath exists
Most fitness calculators hide one formula behind one number. TrainMath shows the math: three 1RM formulas side by side, Riegel predictions with the exponent visible, Mifflin-St Jeor solved step by step. If a number on this site cannot be checked by hand, it should not be here.