Fitness & Performance Calculators — United Kingdom

Turn a goal time for 5 km, 10 km, a half marathon or a marathon into the pace per kilometre and per mile, the speed, and even splits.

Predict your finish time at another distance from a recent race with Riegel's formula, T2 = T1 × (D2 ÷ D1)^1.06.

Interval session arithmetic — the pace for each rep, the rest between them, and how long the whole session takes.

Your speed over a timed sprint — a 40-yard dash, a 30 m fly or a 100 m — in metres per second, km/h and mph, with how it compares.

Turn a one-rep max into the working weights for every common training percentage, from 50% warm-ups to 95% singles.

Score a powerlifting total (or a single lift) with the DOTS formula, which adjusts for bodyweight so lifters of different sizes can be compared.

Calculate the volume load of a lift — sets × reps × weight — the tonnage that programmes track from week to week, with the total relative to your bodyweight.

Estimate VO2 max from the Cooper 12-minute run test — the distance you cover in twelve minutes — or from a 1.5-mile run time.

Estimate the calories an activity burns from its MET value, your weight and the minutes spent — walking, running, cycling, swimming, lifting and more.

Convert a step count into kilometres and miles using a stride length estimated from your height, with the calories those steps burned.

Measure how much your heart rate falls in the first minute after stopping exercise — a simple marker of recovery and cardiovascular fitness.

Your acute-to-chronic workload ratio — the single best-known predictor of soft-tissue injury — from this week’s load against the last month’s.

Your sweat rate from a weigh-in before and after exercise — and the drinking rate that keeps you within a safe fluid deficit.

A training block laid out week by week — the load rising by a set percentage each week from a starting figure, a deload week at the end, and the next block starting a step higher — with the peak week, the total for the block, and a check that the week-to-week jumps stay inside a safe ramp.

Your estimated VO₂ max from the level and shuttle you reached in the beep test (multistage fitness test), with the distance you ran and the speed of the final level.

Your SWOLF score — strokes plus seconds for one length — with pace per 100, distance per stroke and stroke rate, and what the score says about your efficiency.

Your critical swim speed — the pace you could hold for a long, hard swim — from 400 m and 200 m time trials, with the pace per 100 m and paces for endurance, threshold and race sets.

A taper plan for the weeks before a race — how much to cut your weekly volume, week by week, for a 5K through to a marathon or an Ironman — from your peak training week.

The calories a workout burned from your average heart rate, its length, and your age, weight and sex — the formula fitness watches use when they have no power or pace data.

Work out your bike speed from cadence, chainring and sprocket teeth and wheel circumference — and see the gear ratio, gear inches and metres of development.

Turn a swim distance and time into pace per 100 metres and per 100 yards, speed, and the time for a 400 m, 750 m or 1,500 m at that pace.

Estimate how long a hike takes with Naismith's rule — an hour for every 5 km plus an hour for every 600 m of climb — with an allowance for breaks.

Your functional threshold power from a 20-minute test, the seven training zones it sets, and your power-to-weight ratio.

The power it takes to ride at a given speed — on the flat or a gradient — from rider and bike weight, aerodynamic drag, rolling resistance and drivetrain losses, with the share each one takes.