Sports Calculators

Calculate pace per mile and per kilometer from any distance and finish time, with 5K/10K/half/marathon split projections.

Convert between minutes per kilometer and minutes per mile in either direction.

Compute your Jack Daniels VDOT score from a recent race time. VDOT is a single-number proxy for current running fitness.

Predict equivalent race times for other distances based on a recent race, using the McMillan exponent (similar to the Riegel formula).

Convert between cadence (steps per minute), stride length, and running speed.

Predict your race finish time given a target pace and distance.

Predict your time at any distance using Riegel's formula T₂ = T₁ × (D₂/D₁)^1.06.

Compute the five training-pace zones (recovery to VO₂max) from your lactate-threshold pace.

W/kg = sustained power (W) / body weight (kg). Maps to USAC category and Coggan rider type.

Functional Threshold Power = 20-min average power × 0.95. The standard cycling test protocol.

Time = distance / speed. Convert any of {distance, speed, time} given the other two.

kcal ≈ avg watts × hours × 3.6 — direct from work done (kJ ≈ kcal at 25% gross efficiency).

Ratio = front teeth / rear teeth. Gear inches = ratio × wheel diameter (in).

Grade % = rise / run × 100. Convert to angle (degrees) and category (Cat 4-HC).

Swim pace per 100 m and per 100 yd from total distance and time.

CSS = (400m time − 200m time) / 200, in seconds per metre. Per Salo et al. — the swim equivalent of FTP.

SWOLF = stroke count + seconds for one pool length. Lower = more efficient.

Laps = ⌈target distance / pool length⌉. Convert any target distance to laps in any pool.

1RM from a sub-max set using Brzycki, Epley, and Lombardi formulas — three estimates side by side.

Wilks score normalizes powerlifting total across bodyweight categories (men + women coefficients).

Plate breakdown per side: 45 / 35 / 25 / 10 / 5 / 2.5 lb (or 25 / 20 / 15 / 10 / 5 / 2.5 / 1.25 kg).

Working set weight × {40%, 55%, 70%, 85%} → warm-up progression for the working set.

Volume = sets × reps × weight. Total tonnage moved per session, week, or block.

Map RPE 6-10 across 1-12 reps to % of 1RM (Tuchscherer / Reactive Training Systems table).

DOTS = total × 500 / polynomial(bw). The IPF's 2020 replacement for Wilks; men + women coefficients (Konertz).

Project weekly weight progression with compound % growth: w_n = w₀ × (1 + r)^n. See exact weights for next 1-12 weeks.

When to take a deload week based on training intensity (avg RPE), weekly volume (sets/muscle), and weeks accumulated.

Convert RPE (Rate of Perceived Exertion) to RIR (Reps in Reserve). RIR = 10 − RPE on the Tuchscherer scale.

Target HR = ((max HR − resting HR) × intensity) + resting HR. The HRR (heart rate reserve) method.

Compare Tanaka, Fox (220−age), Gulati (women), and Nes formulas for age-based max HR.

Recommended rest days = base + intensity adjustment − sleep credit + age adjustment.

AC:WR = 7-day training load / 28-day average. Sweet spot 0.8-1.3; >1.5 raises injury risk.

kcal = MET × weight (kg) × hours. Compendium MET values for 14 common activities.

Sweat rate (L/hr) = (pre-weight − post-weight + fluid intake) / duration.

Predict 5K from another race using Riegel formula: T₂ = T₁ × (D₂/D₁)^1.06.

Predict 10K via Riegel: T₂ = T₁ × (D₂/D₁)^1.06.

Predict 13.1 mi via Riegel.

26.2 mi via Riegel. Most accurate from a recent half marathon.

VO2max ≈ (distance in meters − 504.9) / 44.73. Cooper test estimates aerobic fitness.

LT pace ≈ pace you can hold for 60 min. Estimate from recent race or HR zone.

kcal/km ≈ 0.97 × bodyweight (kg). Foundational metric for marathon fueling.

Average pace hold; predict halfway split for negative-split race plan.

Daily protein need = body weight × g/kg target. RDA 0.8 g/kg; athletic 1.6-2.2 g/kg.

Base 0.5 oz/lb (33 mL/kg) + 12 oz per 30 min exercise.

Caffeine t½ ≈ 5 hr in adults. Dose × 0.5^(hours/5) = remaining.

Loading: 0.3 g/kg/day for 5-7 days. Maintenance: 0.03 g/kg/day (~3-5g).

Light skin: ~10-15 min midday sun produces 1000-3000 IU. Darker skin needs 3-6× longer.

AHA limit: 1500 mg ideal, 2300 mg max. Athletes lose 500-1500 mg/hr in sweat.

Adults: 25 g women / 38 g men. Most US adults get half that.

BAC = (drinks × 0.6) / (weight × Widmark factor) − (0.015 × hours). NHTSA Widmark formula.

Compute bicycle gear ratio, gear inches, metres of development, and gain ratio from chainring, cog, wheel size, and crank length.