3:45 marathon pace

A 3:45 marathon is 8:35 per mile or 5:20 per km, with halfway at 1:52:30. Every mile and km split, the arithmetic, and how to train for it.

8:35

Pace per mile

5:20

Pace per km

1:52:30

Halfway split

6.99 mph

Speed

Every split for 3:45

Cumulative clock time at each mile or kilometre marker on even pace, for 3:40:00, 3:45:00 and 3:50:00. Switch units with the toggle. Formula: goal seconds × distance covered ÷ race distance.

Splits per

Mile	3:40:00	3:45:00	3:50:00
1	8:23	8:35	8:46
2	16:47	17:10	17:33
3	25:10	25:45	26:19
4	33:34	34:20	35:05
5	41:57	42:54	43:52
6	50:21	51:29	52:38
7	58:44	1:00:04	1:01:24
8	1:07:08	1:08:39	1:10:11
9	1:15:31	1:17:14	1:18:57
10	1:23:55	1:25:49	1:27:43
11	1:32:18	1:34:24	1:36:30
12	1:40:41	1:42:59	1:45:16
13	1:49:05	1:51:34	1:54:02
14	1:57:28	2:00:09	2:02:49
15	2:05:52	2:08:43	2:11:35
16	2:14:15	2:17:18	2:20:21
17	2:22:39	2:25:53	2:29:08
18	2:31:02	2:34:28	2:37:54
19	2:39:26	2:43:03	2:46:40
20	2:47:49	2:51:38	2:55:27
21	2:56:13	3:00:13	3:04:13
22	3:04:36	3:08:48	3:12:59
23	3:12:59	3:17:23	3:21:46
24	3:21:23	3:25:58	3:30:32
25	3:29:46	3:34:32	3:39:19
26	3:38:10	3:43:07	3:48:05
26.22	3:40:00	3:45:00	3:50:00

Cumulative clock time at each mile marker, at perfectly even pace over 42.195 km. Nobody runs even splits and nobody should try to; use these as the line you are measuring drift against, not as an instruction. The difference between the number here and the number on your watch is information — a minute up at 15 km is a race you are about to lose.

Your exact pace

The chart moves in fixed steps. Enter the marathon time you actually want.

hours

min

sec

Units

Per mile: 8:35
Per km: 5:20
Speed: 6.99 mph

Checkpoints at even pace

5 mi: 42:54
10 mi: 1:25:49
Half: 1:52:30
20 mi: 2:51:38

The same goal as a 1% negative split

First half: 1:53:38
Second half: 1:51:23

Pace band: every mile, ready to print

Band

18:40
217:20
326:00
434:40
543:20
652:00
71:00:40
81:09:20
91:18:00
101:26:40
111:35:21
121:44:01
131:52:41
142:01:11
152:09:41
162:18:11
172:26:41
182:35:10
192:43:40
202:52:10
213:00:40
223:09:09
233:17:39
243:26:09
253:34:39
263:43:08
26.23:45:00

Even-pace arithmetic: goal seconds × distance covered ÷ race distance. It assumes you can hold the pace, which is the part training decides.

A plan for a 3:45 marathon

Your plan · free preview

16-week marathon plan

Intermediate · 4 runs a week

Starts next Monday

Level

Length

Race date

Week 1Race week

Longest run: 20mi
Biggest week: 42mi
Whole plan: 464mi
Goal pace: 8:35/mi

Goal pace is arithmetic: 3:45:00 ÷ 26.2 mi. It is not a training zone.

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Week by week · 16 weeks · in miles

16-week marathon plan, week by week
Week	Phase	Long run	Total
1	base	9.9	22
2	base	11	24
3	base	12	27
4	cutback	8.7	19
5	build	14	30
6	build	15	32
7	build	16	35
8	cutback	11	24
9	build	17	38
10	build	19	41
11	peak	20	42
12	peak	20	42
13	taper	13	27
14	taper	8.7	19
15	taper	5.6	12
16	race	26.2	31

The pace, and the arithmetic

A 3:45 marathon is 8:35 per mile, or 5:20 per kilometre, held for 26.2 miles (42.195 km). On even pace you pass halfway at 1:52:30 and 20 miles at 2:51:38. To finish under 3:45, run 8:34 per mile, which finishes in 3:44:36.

How the numbers are worked out

3:45:00 is 13,500 seconds.
Per mile: 13,500 ÷ 26.2188 miles = 514.9 s = 8:35.
Per kilometre: 13,500 ÷ 42.195 km = 319.9 s = 5:20.
At halfway: 13,500 × 21.0975 ÷ 42.195 = 6,750.0 s = 1:52:30.
At 20 miles: 13,500 × 20 ÷ 26.2188 = 10,298.0 s = 2:51:38.
At 40 km: 13,500 × 40 ÷ 42.195 = 12,797.7 s = 3:33:18.
Speed: 26.2188 miles ÷ 3.75 h = 6.99 mph (11.25 km/h).

Every split on this page uses one formula: goal seconds × distance covered ÷ race distance, rounded to the nearest second. A mile is 1.609344 km, so the marathon is 26.2188 miles. The marathon pace chart applies the same formula to every realistic finish time.

Checkpoints

Finish	/mi	/km	5 mi	10 mi	Half	20 mi
3:35:00	8:12	5:06	41:00	1:22:00	1:47:30	2:44:00
3:40:00	8:23	5:13	41:57	1:23:55	1:50:00	2:47:49
3:45:00	8:35	5:20	42:54	1:25:49	1:52:30	2:51:38
3:50:00	8:46	5:27	43:52	1:27:43	1:55:00	2:55:27
3:55:00	8:58	5:34	44:49	1:29:38	1:57:30	2:59:16

Checkpoints are even-pace clock times for the marathon (42.195 km / 26.22 mi), on mile markers or kilometre markers to match the toggle. Underlined times open that goal's page, with every split.

Where 3:45 sits in the field

RunRepeat's finish-time percentiles (35M results across 28,000+ races, as printed on our average marathon time page) place 3:45:00 between the fastest 10% (3:31:46) and the fastest 30% (4:02:56) of all finishers. For men it sits between the fastest 10% (3:22:40) and the fastest 30% (3:53:07); for women, between the fastest 1% (3:11:35) and the fastest 10% (3:49:22).

Read the other way: 3:45 beats more than 70% of all finishers in that data, and for women it is inside the fastest 10%.

3:45:00 is also the Boston Marathon qualifying standard for women and non-binary athletes aged 45 to 49, for both the 2027 and 2028 races. Meeting it is not enough on its own: the 2027 cut-off was 5:17, so those runners needed 3:39:43 or faster to be accepted. Details on our Boston qualifying times page.

In New York, 3:45:00 is the entry standard for men aged 65 to 69 (NYC Marathon qualifying times).

How to train for a 3:45 marathon

Check the goal before you train for it. Riegel's formula, T2 = T1 × (D2 ÷ D1)^1.06 (Riegel, American Scientist 69(3), 1981), says 3:45:00 for the marathon is worth:

Half marathon: 13,500 × (21.0975 ÷ 42.195)^1.06 = 6,475 s = 1:47:55.
10K: 13,500 × (10 ÷ 42.195)^1.06 = 2,935 s = 48:55.

Riegel is optimistic when it predicts a marathon from a shorter race. Treat a recent half marathon near 1:48 as the minimum evidence for 3:45, not proof. Run your own recent result through the race time predictor, and use the VDOT calculator to turn it into training paces.

Then pick a plan. The intermediate level fits a 3:45 attempt: it assumes a marathon behind you and a target time in mind. The free 16-week intermediate marathon plan is 4 runs a week, peaking at 68 km with a 32 km long run, with cutback weeks and a taper. Put goal-pace miles at 8:35 inside the later long runs, so race pace is familiar before race day. Either side of it, 3:30 marathon pace is 8:01 per mile and 4-hour marathon pace is 9:09.

Even splits are the reference line, not the plan

Nobody runs a perfect even split, and the opening of a marathon feels easy at almost any pace. Use these times as the line you measure drift against: if you are well ahead early, you are spending the end of the race at the start.

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Fair questions

What pace is a 3:45 marathon?

8:35 per mile, or 5:20 per kilometre: 13,500 seconds ÷ 26.2188 miles = 514.9 s, and ÷ 42.195 km = 319.9 s. Halfway comes at 1:52:30.

Is a 3:45 marathon good?

Yes, by the published numbers. RunRepeat's finish-time percentiles put the fastest 30% of marathon finishers at 4:02:56 or better and the fastest 10% at 3:31:46, so 3:45 sits between them. For women the fastest-10% mark is 3:49:22, so a 3:45 woman is inside it.

Is 3:45 a Boston qualifying time?

Yes for women and non-binary athletes aged 45 to 49: 3:45:00 is their B.A.A. standard for 2027 and 2028. The standard only lets you apply. With 2027's 5:17 cut-off, they needed 3:39:43 or faster.

What half marathon time predicts a 3:45 marathon?

About 1:47:55 by Riegel's formula (13,500 × 0.5^1.06). The formula assumes marathon training, so treat a recent half at that time as the minimum evidence.