A practical toolkit for runners and athletes
Answers for your next training decision.
Estimate race pace, set training zones, plan calories, and understand body metrics—without wading through jargon. Start with the question you actually have.
Popular starting points
Go straight to the useful part.
These are the questions athletes ask most often. Each tool explains the inputs, output, and assumptions on its own page.
Race pace & splits
Turn a recent result into 5K, 10K, half, or marathon targets.
Easy-run intensity
Estimate Zone 2 and see how resting HR changes the range.
Maintenance calories
Find a starting TDEE before deciding on a deficit or surplus.
Composition metrics
Review BMI, body fat, waist ratio, and lean mass with context.
Fast estimates
Try it before you commit.
Useful for orientation. For decisions, open the full calculator and read the method behind the number.
Zone 2 range
Age + resting HR gives a more individualized starting range than age alone.
Pace to speed
Convert a running pace into km/h for treadmill or training notes.
Calorie starting point
Subtract a conservative goal from maintenance; avoid extreme targets.
The full library
Find the calculator that answers your question.
Search by outcome or filter by topic. Save tools you want to return to on this device.
Running Pace Calculator & Race Predictor
Use a recent race or target distance to build pace, split, and finish-time estimates.
Zone 2 Running Calculator
Compare HRR, Tanaka, and MAF approaches for a practical aerobic range.
Heart Rate Training Zones
Map five effort zones from active recovery to high-intensity work.
Running Calorie Burn Calculator
Estimate energy cost from body weight, distance, pace, and effort assumptions.
TDEE Calculator
Estimate maintenance calories across baseline metabolism, activity, and training.
Weight Loss Macro Calculator
Set a protein-forward macro starting point for sustainable fat loss.
Macronutrient Ratio Calculator
Compare balanced, endurance, and lower-carb splits against a calorie target.
Calorie Requirement Calculator
Find a daily calorie estimate for maintenance, weight loss, or lean gain.
Basal Metabolic Rate (BMR)
Estimate baseline energy needs before activity and exercise are added.
Resting Metabolic Rate (RMR)
Estimate resting energy expenditure for active people and trainees.
BMI, BMR & WHR Calculator
Review three screening metrics together and understand their limitations.
Lean Body Mass (LBM)
Estimate fat-free mass using established anthropometric equations.
Ideal Body Weight (IBW)
Compare classic clinical formulas against your height and current weight.
AI Running Shoe Finder
Match cushioning, foot shape, strike pattern, and weekly mileage to shoes.
Personalized 8-Week Training Plan
Build a plan with progressions, cross-training, and recovery built in.
A calculator gives you a starting estimate, not a diagnosis or guarantee. Interpret results with your training history, how you feel, and advice from a qualified professional when needed.
How to use a result
Useful numbers need context.
Start with the estimate. Then compare it with your real training, recovery, and goals. The best result is the one that helps you make a better next decision.
- Check units and inputs before trusting the output.
- Treat ranges as ranges; avoid false precision.
- Repeat measurements consistently to see a trend.
- Ask a qualified professional when medical concerns are involved.
Questions people ask
Before you use a calculator
Why can two tools give different answers?
They may use different equations, activity assumptions, units, or definitions. Compare the method and use the output as a practical range.
Which calculator should I start with?
Choose the question closest to your goal above. For running, start with pace or Zone 2. For nutrition, start with TDEE before macros or a deficit.
Are the results medical advice?
No. These are educational estimates, not diagnosis or treatment.