Calculators built for pacing, training, and race execution
Run Regimen prioritizes tools that help runners answer practical questions: what race time is realistic, what pace should I train at, how should I split the effort, and what changes when conditions get harder.
Start here if you are building training around a race goal
Running Performance Calculator
Get VDOT, race predictions, training paces, and next-step interpretation.
VDOT Calculator
Turn a recent race result into training paces and fitness context.
Pace Calculator
Convert pace, finish time, distance, and speed for race planning.
Training Zones Calculator
Build heart rate and pace zones for aerobic, threshold, and VO2max work.
Split Calculator
Plan even or negative splits for race-day pacing.
Race Strategy Calculator
Match pacing, fueling, and hydration to race duration.
Race Time Predictor
Predict finish times with training-adjusted scenarios and pace bands.
Use these when your training question is more specific
These tools can be useful, but they are secondary to the core pacing and training workflow. Start with the core tools first unless you already know the exact question you are trying to answer.
VO2max Calculator
Estimate aerobic capacity from race performance or field tests.
Balke 15-Minute Run Test Calculator
Estimate VO2max from a 15-minute run test with Balke and Horwill equation context.
Cooper 12-Minute Run Test Calculator
Estimate VO2max, pace, speed, and field-test confidence from a 12-minute run.
Critical Speed Calculator
Estimate Critical Speed and D-prime from running time trials or race results.
Magic Mile Calculator
Estimate race paces and finish times from a hard one-mile time trial.
Lactate Threshold Calculator
Estimate threshold pace and structure tempo-oriented training.
Heart Rate Zones
Calculate a simple five-zone heart rate system using max HR or reserve.
Cadence and Stride Calculator
Interpret cadence and stride length in a running-specific context.
Age Grading Calculator
Compare performances across ages with WMA standards.
Humidity Calculator
Adjust pacing and hydration expectations for hot and humid conditions.
Mileage Increase Calculator
Plan safer mileage progression with recovery weeks and guardrails.
Power Calculator
Estimate running power when you need a rough watts-based benchmark.
FTP Calculator
Estimate threshold power for runners using power-based training.
TSS Calculator
Quantify session load with a power, pace, or heart-rate input.
Route Calculator
Plan distance and elevation when route work matters to the session.
Calories Burned Calculator
Estimate energy expenditure for running and walking with terrain adjustments.
Hiking Calorie Calculator
Estimate hiking calorie demand with elevation gain, terrain, and backpack load.
Treadmill Calorie Calculator
Estimate treadmill calorie burn with speed, incline, and target-calorie planning.
Treadmill Pace Calculator
Convert treadmill speed, pace, and finish-time goals with incline context.
Run-Walk Pace Calculator
Plan run-walk ratios, average pace, finish time, splits, and goal pace.
Tinman Pace Calculator
Generate Tinman training paces using Critical Velocity methodology.
Kosmin Test Calculator
Predict 800m or 1500m readiness from repeated 60-second field-test efforts.
Grade Adjusted Pace
Convert uphill and downhill pace to a flat-ground equivalent.
Altitude Adjustment
Adjust race pace and finish time for elevation with acclimatization.
Quick conversions and everyday calculations
Simple converters for step-based estimates. These are useful for general fitness tracking and walking metrics.
Steps to Distance
Convert steps to miles and kilometers with step-length assumptions.
Steps to Miles Calculator
Answer common steps-to-miles conversions with walking, running, and custom step-length options.
Steps to Km Calculator
Convert step count to kilometers with height, step length, and activity context.
Steps to Calories
Estimate calories burned from steps using body weight, step length, activity type, and MET context.
Understand the methods behind the tools
Each concept guide explains the theory a calculator is built on. Read the guide to understand why the numbers matter, then use the tool to apply them to your data.
What Is VDOT?
How VDOT converts a race result into training paces and race predictions.
Related tools: VDOT Calculator, Running Performance Calculator
VO2max Explained
What VO2max measures, how it differs from VDOT, and how to improve it.
Related tools: VO2max Calculator
Training Zones Calculator
How pace and heart rate zones structure effective training.
Related tools: Heart Rate Zones, Race Strategy Calculator