Running Tools

Free calculators for every phase of training and race day. No account required.

Race Calculators

Predict marathon finish time from 5K, 10K, or half marathon using the Riegel formula.

Race Equivalency Chart

See equivalent effort times across all common race distances at once.

Mid-Race Finish Estimator

Project your finish time from current distance and elapsed time.

Negative Split Planner

Plan first and second half splits for a smart, controlled race.

Training Pace Tools

Training Pace Calculator

Get easy, tempo, long run, and VO2max paces from your marathon goal.

VDOT Calculator

Estimate VO2max and Jack Daniels training paces from any race result.

Convert between min/mile, min/km, mph, and km/h in one step.

Pace Band Generator

Printable mile-by-mile or 5K split table for your target race time.

Taper Calculator

Week-by-week mileage targets for the three weeks before your marathon.

Adjustment Tools

Heat & Humidity Adjuster

Adjust your goal pace for temperature and humidity race conditions.

Altitude Pace Adjuster

Estimate how much slower to run when racing above sea level.

Calorie Burn Calculator

Estimate calories burned by body weight, distance, and effort.

Standards & Reference

Boston Qualifier Checker

Enter age, gender, and finish time to check BQ status and buffer.

Age Grade Calculator

Compare your performance to World Athletics open age standards.

BQ Standards Table

Full Boston Athletic Association qualifying times by age group and gender.

Marathon Ballot Dates

Ballot and registration windows for London, Tokyo, NYC, Berlin, Chicago.

Running Glossary

Plain-English definitions of training terms, race jargon, and common metrics.

Want a personalized training plan?

Dromotelo builds an 18-week Pfitzinger plan around your goal time and connects to Garmin and Strava.