Marathon Race Pace Predictor: What Is Your 5K Equivalent?

How do you know if you are ready to break the 4-hour barrier? Or perhaps you are chasing a Sub-3? The most accurate way to predict your marathon potential is to look at your current speed over 5 kilometers.

Use the table below to find your current 5K time and see what your equivalent performance should be across other distances, from the Mile to the full Marathon.

Equivalent Performance Table

Current 5K Time	Mile Equivalent	10,000m Time	Half Marathon	Marathon Goal
30‘	08’55”	1:02′	2:17′	4:41′
29‘	08’41”	1:00′	2:13′	4:34′
28‘	08’14”	57′	2:07′	4:22′
27′	08’01”	56′	2:04′	4:16′ (Avg Finish)
26′	07’38”	53′	1:58′	4:04′
25′	07’27“	52′	1:55′	3:59′ (Sub 4)
24′	07’07”	50′	1:50′	3:49′
23′	06’49”	48′	1:46′	3:40′
22′	06’25”	45′	1:40′	3:28′
21′	06’10”	43′	1:36′	3:21′
20′	05’50”	41′	1:31′	3:10′
19′	05’32”	39′	1:27′	3:01′
18′	05’16“	37′	1:23′	2:53′ (Sub 3)
17′	4’57”	35′	1:18′	2:43′
16′	4’37”	33′	1:12′	2:32′
15′	4’19”	31′	1:08′	2:23′
14′	4’04”	29′	1:04′	2:14′
13′	3’46”	27′	59’30”	2:04′

Important: The “Endurance Gap”

It is important to remember that these times are equivalents. This means that if you can run a 25 minutes 5K, you have the aerobic engine required to run a 3:59 marathon.

However, you still need to do the work. The shorter the race, the more you rely on raw speed. The longer the race, the more you rely on fat metabolism and muscular endurance. To “lock in” your predicted marathon time, your training must include:

• Weekly long runs to build mitochondrial density.
• Marathon-specific pacing sessions.
• A calculated fueling strategy (the “Fourth Discipline”).

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Is your Marathon time slower than the chart suggests?

If you can run a 23-minute 5K but struggle to break 4 hours in the marathon, you likely have an Endurance Gap. This is where my coaching comes in. We focus on building your “diesel engine” so you can maintain your 5K speed over the full 26.2 miles.

Analyze My Training Plan | View Autumn 2026 Marathons

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