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Fitness Calculator

Calculate 1RM, calories burned, running pace, and VO2 max

Fitness Calculator Guide

A fitness calculator bundles everyday tools: 1RM estimates, calorie burn (METs), running pace/speed, and simple VO2 max approximations. It helps plan training loads, sessions, and energy balance.

What is Fitness Calculator?

The fitness calculator converts your inputs into training-ready numbers: maximum strength estimates, calories for activities, paces for workouts, and conditioning indicators—so you can plan and track progress.

How to Use the Fitness Calculator

  1. 1RM: enter lifted weight and reps; choose Epley or Brzycki.
  2. Calories (METs): pick activity MET, enter body weight and duration.
  3. Pace/Speed: provide distance and time to compute splits and pace.
  4. VO2 max (field): enter a test result (e.g., 1.5-mile time) to estimate VO2 max.
  5. Save common workouts and compare progress over time.

Formulas & Methods

  • 1RM (examples):
    • Epley: 1RM = w * (1 + r/30)
    • Brzycki: 1RM = w * 36 / (37 - r) (valid <=10-12 reps)
  • MET calories: kcal/min ~ MET * 3.5 * mass_kg / 200
    Total kcal = (kcal/min) * minutes
  • Pace/speed: pace = time/distance; speed = distance/time
  • VO2 max (example field estimate): from a 1.5-mile run in minutes t, VO2 ~ 3.5 + 483 / t (illustrative).

Assumptions & limitations

  • 1RM equations are estimates; technique and training status matter.
  • METs are averages; individual physiology varies.
  • VO2 max formulas are approximations from field tests, not lab values.

Examples

Example A — 1RM
w = 100 kg, r = 5 -> Epley: 1RM ~ 100*(1 + 5/30) = 116.7 kg; Brzycki: 100*36/(37-5) = 112.5 kg.

Example B — MET calories
Running MET = 9.8, mass = 75 kg, 45 min -> kcal/min ~ 9.8*3.5*75/200 ~ 12.86 -> total ~ 579 kcal.

| Tool | Inputs | Output | |---|---|---| | 1RM | Weight, reps, formula | Estimated max | | METs | Activity, kg, minutes | Calories | | Pace | Distance, time | min/mi or min/km |

Pro Tips & Best Practices

  • Keep rep ranges in the valid window for your 1RM formula.
  • Use consistent body weight and conditions when comparing MET calories.
  • For intervals, compute split targets to control pacing.
  • Re-test VO2 estimates every 6-8 weeks to track adaptation.
  • Pair with BMR/Calorie tools for energy balance planning.

Related Calculators

FAQ

Q: How is 1RM estimated?

A: Common formulas: Epley 1RM = w*(1 + r/30) and Brzycki 1RM = w*36/(37 - r), where w is lifted weight and r reps.

Q: How are calories burned estimated?

A: We use MET values: kcal/min ~ MET * 3.5 * kg / 200; total kcal = rate * minutes.

Q: How do I compute running pace and speed?

A: Pace = time/distance; speed = distance/time. Convert between min/mi and min/km as needed.

Q: What is VO2 max?

A: An estimate of maximal oxygen uptake. Field tests (e.g., 1.5-mile run) or age-graded formulas give approximations.

Q: Are these medical prescriptions?

A: No—use them as fitness planning tools, not medical advice.

Compliance note: Informational only; not medical advice.

Call to Action

Estimate your 1RM, pace, and calories for today's session—save the numbers to progress your training with intent.