How DialPace calculates

Every number on DialPace comes from a published formula with a named, primary source. Nothing here is invented or tuned to look good — this page explains the standards behind the calculators, and the calculator's own page lists the exact reference it uses.

Our principles

• Published formulas only. If a calculation has no public, primary source, we don't ship it.
• Primary sources, cited per tool. Each calculator credits the original research or governing body — not a blog or a vendor.
• Consistent units. We convert your input to SI, compute in SI, and format on the way out, so the mile view and the kilometre view of the same result never disagree.
• Estimates, with assumptions stated. These are models of population averages; your result is a starting point, not a promise. See our disclaimer.
• Corrections welcome. Found a discrepancy? Tell us and we'll fix it.

The formulas we use

Race prediction & equivalent times

Finish-time predictions across distances use Pete Riegel's endurance model (T₂ = T₁ × (D₂ / D₁)^1.06), with Dave Cameron's model as a sharper alternative around the half and full marathon. Both are empirical fits to large race datasets and assume appropriate training for the target distance.

Training paces & VO₂

Training zones and VDOT come from Jack Daniels' Running Formula — a VO₂-based model that turns a recent race into easy, marathon, threshold, interval and repetition paces. VO₂max estimates follow the same oxygen-cost relationships.

Heart-rate zones

Zones use the Karvonen heart-rate-reserve method (which accounts for your resting heart rate) alongside simple percent-of-maximum, so you can pick the model your watch uses.

Age grading

Age-graded scores use the World Masters Athletics (WMA) age factors, the standard for comparing performances across ages and sexes.

Grade & environment adjustments

Hill and grade-adjusted pace draw on Minetti and colleagues' measurements of the energy cost of running on a gradient; heat and altitude adjustments apply established physiological cost factors. Each adjustment tool names its specific source.

Physiology & body composition

BMI follows the WHO definition; resting metabolic rate uses the Mifflin-St Jeor equation; running energy expenditure uses ACSM's metabolic equations and MET values; body-fat estimates use the documented anthropometric methods cited on each tool. These health-adjacent tools are estimates only and are not medical advice.

Cycling & triathlon

Cycling tools use standard definitions — FTP from a 20-minute test, power-to-weight in W/kg, gear inches from the drivetrain — and the swim/triathlon tools use critical-speed and critical-swim-speed models.

Want the exact reference for a specific number? It's on that calculator's page. Browse all running calculators →