Running performance tools for 5K to marathon training

Calculate smarter training paces, race targets, and next steps.

Run Regimen helps runners turn recent performances into useful training decisions. Use evidence-based calculators for VDOT, pace, splits, and training zones, then follow the linked guides to understand what the result means in practice.

Methodology

Transparent formulas, not black-box outputs

See how methods and updates are documented

Daniels' VDOT

Used for training paces and performance equivalence.

Riegel formula

Used for race prediction across distances.

Karvonen method

Used for heart rate reserve and zone calculation.

ACSM guidance

Used when exercise physiology conventions are needed.

Core tools

The tools most runners should use first

View the full tool library
Why trust the site

Built like a training reference, not a calculator farm

Transparent methodology

Each major calculation is tied to a named method, assumptions, and supporting references.

Interpretation over raw output

The goal is not just to compute a number. The goal is to explain how to use that number in training.

Focused scope

The site is optimized around running performance, race pacing, and training structure from 5K to marathon.

Editorial accountability

Guides, updates, and correction standards are published in the editorial policy and trust pages.

Start with the strongest entry point

If you have one recent race result, the Running Performance Calculator is the best first step. It gives VDOT, race equivalence, pace ranges, and a more useful starting point for training.

Open the main calculator
FAQ

Common questions

Who is Run Regimen for?

The site is built for runners training from 5K to marathon who want better pacing, better training structure, and clearer interpretation of their numbers.

Is this a calculator directory or a training site?

It is a running performance platform. The calculators are the entry point, but each one is paired with interpretation, methodology, and practical training guidance.

What should a first-time visitor do?

Start with the Running Performance Calculator if you have a recent race result. Start with the Pace Calculator if you need pace, time, or distance conversions.