Bodybuilding & Gym Calculators
Free gym calculators: plates per side, one-rep max, TDEE and protein. They run in your browser, store nothing and show the formulas they use.
Calculator
Barbell Plate Calculator
Plates per side for any target, with your own inventory, collars, rounding modes, a warm-up ramp and share links.
- You enter
- Target weight, bar, collars, plates
- You get
- Plates per side, warm-ups, share link
Calculator
One-Rep Max Calculator
Estimate your max from any set of 1–12 reps with three formulas, then get percentage, rep-target and warm-up tables.
- You enter
- Weight and reps (1–12)
- You get
- 1RM by 3 formulas, % and rep tables
Calculator
TDEE & Macro Calculator
Maintenance calories from Mifflin-St Jeor (or Cunningham with body-fat %), five goal targets and a macro split.
- You enter
- Age, sex, height, weight, activity
- You get
- Calories for 5 goals, macros
Calculator
Protein Calculator
A daily protein range in grams for gaining, cutting or maintaining, split across your meals.
- You enter
- Bodyweight, goal, meals
- You get
- Daily grams and per-meal amounts
Which calculator do you need?
| Your question | Use | Then read |
|---|---|---|
| What plates go on the bar for 102.5 kg? | Barbell plate calculator | Progressive overload |
| What is my max, and what should I lift for 5s? | 1RM calculator | Strength programs |
| How many calories to bulk or cut? | TDEE calculator | Bulking and cutting |
| How much protein per day and per meal? | Protein calculator | Protein and nutrition |
How these calculators work
Each tool uses published equations: Mifflin-St Jeor (1990) and Cunningham (1980) for energy expenditure; Epley, Brzycki and Lombardi for one-rep max; and the protein ranges from the Morton et al. (2018) meta-analysis and ISSN position stand. The plate calculator is plain arithmetic, working through your actual plate inventory to find the combination with the fewest plates.
All outputs are estimates. Use them as a starting point, then adjust based on your scale trend, training log and how you feel. Nothing you type leaves your device.