Core answer: Pace = target time ÷ distance. For the 42.195 km marathon: sub-4 requires 5:41/km, 3:30 requires 5:00/km, sub-3 requires 4:16/km. First-timers should start at a conservative pace of "goal + 20 minutes" overall.
The pace conversion formula
Pace (min/km) = target finish time (minutes) ÷ distance (km)
Reverse: finish time = pace × distance.
Example: 5:00/km for a marathon = 5 × 42.195 = 211 minutes = 3h31m.
Marathon pace chart
| Goal | Finish time | Per-km pace | 5K split | Half split |
|---|---|---|---|---|
| Sub-3 | 2:59:59 | 4:16 | 21:18 | 1:29:59 |
| 3:15 | 3:15:00 | 4:37 | 23:06 | 1:37:30 |
| 3:30 | 3:30:00 | 4:59 | 24:55 | 1:45:00 |
| 3:45 | 3:45:00 | 5:20 | 26:40 | 1:52:30 |
| Sub-4 | 3:59:59 | 5:41 | 28:25 | 1:59:59 |
| 4:15 | 4:15:00 | 6:02 | 30:12 | 2:07:30 |
| 4:30 | 4:30:00 | 6:24 | 32:01 | 2:15:00 |
| 5:00 | 5:00:00 | 7:07 | 35:34 | 2:30:00 |
| 5:30 | 5:30:00 | 7:49 | 39:07 | 2:45:00 |
| 6:00 (cutoff) | 6:00:00 | 8:32 | 42:37 | 3:00:00 |
Half-marathon pace chart
| Goal | Finish time | Per-km pace |
|---|---|---|
| 1:30 | 1:30:00 | 4:16 |
| 1:45 | 1:45:00 | 4:59 |
| Sub-2 | 1:59:59 | 5:41 |
| 2:15 | 2:15:00 | 6:24 |
| 2:30 | 2:30:00 | 7:07 |
Half-marathon distance: 21.0975 km; pace conventions match the full marathon.
Example: executing a sub-4 plan
Example: targeting 3:59:59 (5:41/km), a robust race plan:
- 0–5 km: 5:50–6:00, a controlled warm-up — conversation pace
- 5–30 km: lock into 5:40–5:45, heart rate at the top of the aerobic zone
- 30–35 km: the wall zone — dropping to 5:50 is fine; take a gel and walk 20 seconds at aid stations
- 35–42 km: if you feel decent, return to 5:40 and push the final 2 km
- Expected finish: 3:56–4:02, within tolerance
Cautionary tale: running the first half at an excited 5:20 (1:52 at halfway), then collapsing to 7:00+ after 30 km, finishing 4:25 — the 3 minutes "banked" early get repaid with 25 minutes of suffering.
Five training pace zones
| Zone | Pace reference (for a 4-hour marathoner) | Purpose | Share |
|---|---|---|---|
| E easy | 6:30–7:00 | Aerobic base | ~60% |
| M marathon pace | 5:41 | Race-specific adaptation | 15% |
| T threshold | 5:10–5:20 | Lactate-threshold endurance | 10% |
| I intervals | 4:30–4:45 | VO2max | 10% |
| R repetitions | Faster | Speed and form | 5% |
Core principle: 80% of your volume should feel slow — easy runs slow enough make the quality sessions count.
First-marathon race-day strategy
- Set a conservative goal: marathon ≈ recent 10K time × 4.6–4.8
- Treat the first 5 km as a warm-up — never let the crowd pull you fast
- One energy gel every 45 minutes; drink at every station (small sips, often)
- Before 30 km, watch only the current-kilometer pace, not the clock
- Slowing down? Walk for a minute and restart — far better than pushing into a blow-up
Common mistakes and myths
- "Bank time early" — glycogen stores are fixed; running 10 s/km too fast gets repaid double after 30 km. Negative splits (faster second half) are how elites race.
- "Steady pace means steady heart rate" — HR drifts upward (+10–15 bpm after 2 hours at the same pace), worse in heat and humidity — watch both effort and HR.
- "100 km/month is enough for sub-4" — sub-4 typically needs 150–200 km/month sustained for 3–6 months; willpower without volume is a fast track to injury.
- "New shoes and watch on race day" — everything needs 50+ km of break-in; nothing new on race day.
Use the [Marathon Pace Calculator](/c/health/marathon) for per-km pace and split tables from any goal time, and the [Heart Rate Calculator](/c/health/heart-rate) for training zones.