Running Calculators
Free, science-based tools for runners. No signup required. Enter your numbers and get instant results.
Every calculator here runs on a named, published method: Jack Daniels' VDOT system, the Riegel fatigue-factor formula, the Karvonen heart-rate-reserve method, Friel's LTHR-based zones, the Minetti grade-adjustment model, not a black-box guess. We'll tell you which one, so you can look it up yourself if you want the full derivation.
Use them on their own to sanity-check a number, or as a starting point before you go deeper: our blog covers the reasoning behind several of these methods in more detail, and if you'd rather have a coach track all of this automatically instead of re-running a calculator every few weeks, that's what Vertical does.
Race prediction
Start here if you're targeting a specific race. These tools turn a recent result, or a planned course, into a realistic goal time, adjusted for the conditions you'll actually run in.
- Race Time PredictorEnter a recent race result and predict your finish time at any distance, from 5K to marathon. Powered by the Riegel formula. Best for runners who've raced recently and want a realistic goal time for a different distance.Calculate →
- Running Performance CalculatorAdjust your race time for altitude, course grade, heat, humidity, wind, and age to find your true sea-level equivalent performance. Useful for comparing two races run in very different conditions, or age-grading a result.Calculate →
- Race Pacing & Fueling PlannerUpload your course GPX and a goal for an elevation-aware, even-effort pacing plan plus a carb, fluid, and sodium timeline mapped to the course. Built for marathon, half marathon, and trail runners racing hilly or unfamiliar courses.Plan my race →
- Pace Band & Splits CalculatorTurn a goal finish time into a printable split-by-split pace band for any distance, with even, negative, or positive splits in km or miles. The race-day cheat sheet for hitting your number.Build my band →
- Boston Qualifying CalculatorFind your Boston Marathon qualifying time by age and sex under the 2026/2027 standards, and see the buffer you actually need to get accepted, not just the line on paper.Check my BQ →
- Grade-Adjusted Pace CalculatorConvert a hilly pace into its flat-ground equivalent using the Minetti cost-of-running model, so you can compare effort across climbs and descents. Built for trail and hilly-course runners.Adjust my pace →
Targeting a specific iconic course? Our race pacing plans load the real course profile for you, so you get elevation-aware splits and a fueling plan without uploading a GPX.
Training zones & fitness
Start here if you want to train at the right effort rather than just run faster. These tools turn a race result or heart rate data into zones you can actually train by: easy days that are genuinely easy, and hard days that hit the intensity they're meant to.
- Training Pace CalculatorGet your personalised training zones from a recent race result: easy, tempo, threshold, and more. Based on Jack Daniels' VDOT system. A good starting point before any structured training block.Calculate →
- Lactate Threshold & LTHR CalculatorEstimate your lactate threshold heart rate and threshold pace from a 30-minute time trial or 5K/10K race. Get five training zones anchored on your threshold. Ideal if you train more by heart rate than by pace.Calculate →
- VO₂ Max EstimatorEstimate your aerobic capacity from any race result. See how your fitness compares to other runners and where you sit on the athlete spectrum. Useful for tracking fitness gains between training blocks.Estimate →
- Heart Rate Zone CalculatorCalculate your five heart rate training zones using Max HR percentage, the Karvonen heart rate reserve method, or LTHR-based Friel zones. Pick whichever method matches the data you already have.Calculate →
- Aerobic Decoupling CalculatorCalculate Pa:HR aerobic decoupling from your run's first and second halves. Under 5% signals a strong aerobic base; over 8% means the effort was above threshold. Best for checking long-run pacing and aerobic base development over time.Calculate →
- Critical Speed & D′ CalculatorFit your critical speed and D′ from two or more maximal efforts, then predict race times from your personal power-duration curve. The two numbers behind Vertical’s pace zones.Fit my curve →
- Age Grade CalculatorScore a race as a percentage of the world best for your age and sex, so a masters runner and a 25-year-old can compare performances fairly. Based on WMA age factors.Calculate →