What is the Marathon Pace Calculator?
A marathon is 26.2188 miles, or exactly 42.195 kilometers. This calculator takes your goal finish time and works out the steady pace you need to hold — expressed as minutes and seconds per mile and per kilometer. It is a universal tool for runners of any country or skill level planning a race-day strategy.
How to use it
Enter your target finish time using the hours, minutes, and seconds fields. For example, a 4-hour marathon is 4 hours, 0 minutes, 0 seconds. Press calculate and you'll see your required pace per mile and per kilometer, plus your total time in seconds for reference.
The formula explained
First the finish time is converted to total seconds: \(T = \text{hours} \times 3600 + \text{minutes} \times 60 + \text{seconds}\). Then pace per mile is simply \(T \div 26.2188\), and pace per kilometer is \(T \div 42.195\). The resulting seconds are converted back into a friendly min:sec format.
$$\text{Pace}_{\text{mile}} = \frac{T}{26.2188}, \qquad \text{Pace}_{\text{km}} = \frac{T}{42.195}$$
Worked example
Goal: finish in 4:00:00. Total seconds \(= 4 \times 3600 = 14{,}400\ \text{s}\). Pace per mile \(= 14{,}400 \div 26.2188 \approx 549.2\ \text{s} \approx\) 9:09 per mile. Pace per km \(= 14{,}400 \div 42.195 \approx 341.3\ \text{s} \approx\) 5:41 per km.
$$\text{Pace}_{\text{mile}} = \frac{14{,}400}{26.2188} \approx 549.2\ \text{s} \approx 9{:}09$$$$\text{Pace}_{\text{km}} = \frac{14{,}400}{42.195} \approx 341.3\ \text{s} \approx 5{:}41$$
FAQ
Why 26.2188 and not 26.2? The official marathon distance is 42.195 km, which equals 26.2188 miles — using the precise figure gives a more accurate pace.
Should I run an even pace? Many runners aim for an "even split" (same pace throughout) or a slight "negative split" (faster second half). This calculator gives your average target pace.
Does it account for hills or weather? No — it gives the flat, even-effort pace. Adjust your strategy for elevation, heat, and aid stations on race day.
