Free tool
Running pace calculator.
One recent race result is all it takes: your VDOT fitness score, the five training paces that should anchor every week, and what you could run at other distances.
VDOT 38.3. Easy pace 6:19 /km, threshold 5:16 /km, interval 4:45 /km.
VDOT fitness score
38.3
Race pace
5:00 /km
| Zone | Pace | Use it for |
|---|---|---|
| Easy (E) | 6:19 /km | Warm-ups, long runs, most of your weekly volume |
| Marathon (M) | 5:28 /km | Steady race-specific running |
| Threshold (T) | 5:16 /km | Tempo runs and cruise intervals (~20–40 min of work) |
| Interval (I) | 4:45 /km | VO₂max repeats, 3–5 min each with equal jog recovery |
| Repetition (R) | 4:31 /km | Short, fast reps for speed and economy |
| Distance | Predicted time | Pace |
|---|---|---|
| 1 mile | 7:24 | 4:36 /km |
| 5 km(your result) | 25:00 | 5:00 /km |
| 10 km | 51:53 | 5:11 /km |
| Half marathon | 1:55:04 | 5:27 /km |
| Marathon | 3:57:55 | 5:38 /km |
Predictions assume equivalent training for each distance — a 5K PR doesn’t buy a marathon without the long runs behind it.
How it works
The calculator uses Jack Daniels’ VDOT model, the standard most running plans are built on. Your race result pins down how much oxygen you can use at race effort (your VDOT); each training pace is then a fixed fraction of that number — easy runs around 70% of it, threshold near 88%, intervals at 100%.
Most runners train too fast on easy days and too slow on hard ones. Running each zone at its actual pace is what makes the hard sessions productive and the easy ones recoverable — it’s the single highest-leverage change in most training weeks.
Use a race (or honest all-out time trial) from the last couple of months. A five-year-old PR will prescribe paces your current legs can’t hold.
Now put those paces to work.
Ugoku builds a full periodized plan from this exact VDOT — sessions, zones and weekly structure, adapting as you log. Also try the 1RM calculator.