Laktic Pace Calculator
Heat-adjusted threshold paces
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Today's threshold paces, adjusted for the heat. Free.
Today's threshold paces, adjusted for the heat. Enter a race PR, track or road, and get LT1, Sub-T and LT2 ranges slowed for the temperature and dew point at your track, now or at practice time. Coaches: add your roster, write a note, and share the board as a card.
Enter a 5000m, 3200m, 3000m, 1600m, mile or 1500m PR, or a 5 mile, 10K, half marathon or marathon PR, and the app computes the Track and Road Performance training zones: Easy, Long Run, Steady, and the three threshold zones LT1, Sub-T and LT2, with race-pace rows for road distances. Miles or kilometres, your choice. Get today's temperature and dew point for your location, pick a practice time for that hour's forecast, search a city or ZIP, or type the numbers yourself, and every pace is slowed by the heat penalty.
The adjustment is scaled by rep length. Short threshold reps with recovery build less heat load than continuous running, so 1–3 minute reps take half the penalty, 4–6 minute reps three-quarters, and 7–10 minute reps and continuous runs the full amount. Within each threshold zone, short reps sit at the fast end of the range, medium reps in the middle, and long reps at the slow end.
Every pace shows the per-mile range and the seconds-per-400 m split, so it goes straight to the track.
For coaches: keep a roster of athletes on your phone and build a workout board for today's conditions. Pick a zone and rep length and see every athlete's heat-adjusted range, fastest first, filtered by group. Write a note on the board and share it as a card, along with today's paces, the heat, a new PR or a finished session. Log a session: type your reps and see hit, hot or cold against today's band. Export the roster as a file, import one from an assistant coach, or copy a share link that opens the same roster in the web version.
How the heat model works: heat score = temperature °F + dew point °F. At 100 or below there is no adjustment. The penalty rises to 10% at 180. Above 180 the app tells you running is not recommended and shows paces at the cap for reference only.
Privacy: your location is used only to fetch the weather and the town name. Athlete names and PRs stay on your device unless you export or share them; share cards are drawn by our server from the numbers on screen and are not stored. Sign-in is optional. No tracking, no ads.
Training guidance, not medical advice. Use judgment in extreme conditions.
Pace engine: Track and Road Performance. Weather data by Open-Meteo.
Ratings & Reviews
Road distances: enter a 5 mile, 10K, half marathon or marathon PR and get race-pace rows next to your training zones. Miles or kilometres, your choice.
Forecast paces: pick the practice time and every pace is set for that hour's heat, so a 10 am board is right at 3 pm.
Coach notes on the workout board, and share cards for the board, today's paces, the heat, a new PR and a finished session.
Log a session: type your reps and see hit, hot or cold against today's band.
A default athlete that loads on launch, "View paces" on every roster row, and a profile screen for signed-in coaches.
Resources: how it works in the coach's own words, Laktic Pro preview, upcoming courses and plans.
Smoother motion, clearer colours, larger touch targets, and a long list of small fixes.
The developer, Travis Mahoney, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Health & Fitness
- Contact Info
- User Content
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Travis Mahoney
- Size
- 29.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
9+
- 9+
- Contains
Health or Wellness Topics
- Copyright
- © 2026 Laktic