Why does this tool only show even splits?

Because even splits are the reference every other pattern is built from. For a descending set, coaches typically take a second or two off each split from this baseline; for a negative split, the even time is the midpoint between the slower first half and the faster second. Producing only the even figure avoids guessing at training intent. There is also evidence behind it: in elite 1500 m freestyle racing, even pacing through the middle of the race beat positive pacing by around 8 seconds overall.

How do I get the pace per 100?

You do not have to work it out any more, the tool reports it. It is the total time divided by the total distance, times 100. For the default, 360 seconds over 400 m gives 0.9 seconds per metre, so 1:30 per 100 m. The pace is reported in whichever unit you entered, so a yards distance gives a per-100-yard figure.

Can I enter the distance in yards?

Yes, select yards next to the distance field. Per-split distances and the pace per 100 then come back in yards. The speed row stays in metres per second whatever you choose, since that is the only figure directly comparable between a 25 yd pool and a metric one.

Does this tool account for rest intervals between repeats?

No. It divides only the working time and distance you enter. If your set is 4 × 100 m on a 2:00 send-off with 30 seconds rest, then the 2:00 covers both swimming and resting. Subtract the total rest from the target time before entering it if you want the splits to describe swimming alone.

Can I use this for open-water swims or triathlons?

The arithmetic works for any distance, but open water is slower than the pool for the same effort: current, chop, sighting, and no walls to push off all cost time. Many swimmers add 5 to 15 percent to pool-derived splits when planning an open-water effort. The tool models none of that, nor the benefit of drafting in a pack.

What is the difference between even splits and negative splits?

Even splits hold the same pace throughout. A negative split means the second half is faster than the first. Race analysis supports the underlying idea: among elite 1500 m freestylers, a slower start was worth about 21 seconds over the full race compared with going out fast. This calculator gives you the average; building the faster-second-half version around it is a manual adjustment.

What if the distance does not divide evenly by the split count?

The tool reports the leg to one decimal place rather than rounding it away, so 400 m in 3 splits shows 133.3 m. That is fine for a time trial but awkward in a pool, where splits land at walls: pick a split count that divides your distance into whole lengths if you plan to swim it as a set.

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Swimming

Swim Split Calculator

Divide a target swim time and distance into even splits, with the pace per 100 they imply.

JCVerified Verified by Jobi Cheriyan, Founder & Builder

Updated 21 August 2026

What this tool does

This calculator divides a target swim time and total distance into equal splits, giving the time and distance for each segment plus the pace per 100 and the speed those splits imply. Enter the distance in metres or yards. The output suits interval sets, even-pace time trials, and race-pacing baselines in the pool or open water.

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Result

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Next steps

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Formula Used

S = \frac{T _{sec}}{n}, d_{s pl i t} = \frac{d _{t o t a l}}{n}, P_{100} = \frac{T _{sec}}{d _{t o t a l}} \times 100

T

Target time in seconds

d

Total distance, metres or yards

n

Number of splits

P_{100}

Pace per 100 of the chosen unit

Disclaimer

This calculator is for educational and informational purposes only. It does not provide medical, nutritional, or training advice. Results are mathematical estimates and may not reflect individual circumstances. Consult a qualified coach, registered dietitian, medical professional, or physiotherapist for personal guidance.

How the Swim Split Calculator works

Give the tool a target time, a total distance in metres or yards, and how many splits you want it divided into. It divides both the time and the distance evenly, then reports the per-split time and distance, the pace per 100 that those splits work out to, and the speed in metres per second. Even splits are the baseline: for a descending set they are the average you build around, and for a negative split they are the midpoint between the slower and faster halves.

The formula

Per-split time (seconds) = (target minutes × 60) ÷ splits
Per-split distance = total distance ÷ splits
Pace per 100 = (total seconds ÷ total distance) × 100

Working the default, a 400 m target in 6 minutes over 4 splits: 6 × 60 = 360 seconds, divided by 4 gives 1:30 per split, and 400 ÷ 4 gives 100 m per split. The pace per 100 m is therefore also 1:30, and the speed is 400 ÷ 360 = 1.11 m/s. When the split count does not divide the distance evenly the tool reports the leg to one decimal place, so 400 m in 3 splits reads 133.3 m rather than a rounded 133.

Why even splits are the right baseline

This is not just an arithmetic convenience. An analysis of 327 elite men’s 1500 m freestyle races swum between 2010 and 2019 found that an even pacing strategy through the middle of the race produced faster overall times than a positive one, by about 8.4 seconds, and that a slower start beat a fast start by roughly 21 seconds (McGibbon et al., 2021). Going out hard costs more than it gains over a distance event, which is exactly what an even-split plan is designed to prevent.

Reading the pace per 100

Pace per 100 is the number swimmers actually talk in, and the tool reports it in whichever unit you entered, so a yards distance gives a per-100-yard pace. Comparing across pool formats takes one extra step, since 100 yards is 91.44 metres, so a per-100-yard pace is about 8.6% quicker than the same speed expressed per 100 metres. The tool also reports speed in metres per second regardless of the unit you entered, which is the one figure that is directly comparable between a yards pool and a metric one.

Where this method is most accurate

The division is exact; what varies is whether a swimmer can hold the pace. Even splits suit steady-state aerobic work, time-trial pacing, and establishing baseline data. Real execution is shaped by accumulating fatigue, stroke-rate drift as effort rises, and turn mechanics, all of which shift within a swim rather than staying constant (Chollet et al., 1997). Open water adds current, chop, sighting, and no walls to push off. The tool divides only the working time and distance you give it, with no allowance for warm-up, cool-down, or rest.

What this tool does not do

It performs arithmetic division. It does not prescribe training intensities, recommend race strategies, or evaluate technique. It does not build descending-split schedules, or work in heart-rate zones, lactate thresholds, or stroke-rate targets. It does not account for pool length, drafting, wetsuit buoyancy, or altitude, and it will not judge whether a target time is realistic for you. No physiological modelling is involved.

Disclaimer

This tool is intended for educational and planning purposes only. It is not medical, health, or training advice. The calculator applies basic arithmetic to user-supplied inputs and does not assess fitness level, health status, or injury risk. Consult a certified swim coach, sports physiologist, or physician before beginning or modifying any training program. Individual results vary based on technique, conditioning, and environmental factors. Use of this tool does not establish a coach-athlete or provider-client relationship.

Questions

Why does this tool only show even splits?: Because even splits are the reference every other pattern is built from. For a descending set, coaches typically take a second or two off each split from this baseline; for a negative split, the even time is the midpoint between the slower first half and the faster second. Producing only the even figure avoids guessing at training intent. There is also evidence behind it: in elite 1500 m freestyle racing, even pacing through the middle of the race beat positive pacing by around 8 seconds overall.
How do I get the pace per 100?: You do not have to work it out any more, the tool reports it. It is the total time divided by the total distance, times 100. For the default, 360 seconds over 400 m gives 0.9 seconds per metre, so 1:30 per 100 m. The pace is reported in whichever unit you entered, so a yards distance gives a per-100-yard figure.
Can I enter the distance in yards?: Yes, select yards next to the distance field. Per-split distances and the pace per 100 then come back in yards. The speed row stays in metres per second whatever you choose, since that is the only figure directly comparable between a 25 yd pool and a metric one.
Does this tool account for rest intervals between repeats?: No. It divides only the working time and distance you enter. If your set is 4 × 100 m on a 2:00 send-off with 30 seconds rest, then the 2:00 covers both swimming and resting. Subtract the total rest from the target time before entering it if you want the splits to describe swimming alone.
Can I use this for open-water swims or triathlons?: The arithmetic works for any distance, but open water is slower than the pool for the same effort: current, chop, sighting, and no walls to push off all cost time. Many swimmers add 5 to 15 percent to pool-derived splits when planning an open-water effort. The tool models none of that, nor the benefit of drafting in a pack.
What is the difference between even splits and negative splits?: Even splits hold the same pace throughout. A negative split means the second half is faster than the first. Race analysis supports the underlying idea: among elite 1500 m freestylers, a slower start was worth about 21 seconds over the full race compared with going out fast. This calculator gives you the average; building the faster-second-half version around it is a manual adjustment.
What if the distance does not divide evenly by the split count?: The tool reports the leg to one decimal place rather than rounding it away, so 400 m in 3 splits shows 133.3 m. That is fine for a time trial but awkward in a pool, where splits land at walls: pick a split count that divides your distance into whole lengths if you plan to swim it as a set.

Sources & Methodology

Divides target time (minutes × 60) and total distance by the split count for equal per-split time and distance, and reports pace per 100 as (total seconds ÷ total distance) × 100 in the unit entered. Speed is always metres per second, converting yards at 0.9144 m, so it stays comparable across pool formats. Outputs even splits only; descending or negative splits require manual adjustment from this baseline.

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Swim Split Calculator

What this tool does

Export Report

How the Swim Split Calculator works

The formula

Why even splits are the right baseline

Reading the pace per 100

Where this method is most accurate

What this tool does not do

Disclaimer

Questions

Sources & Methodology

More in Swimming

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