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Swim Pace Calculator
Pool, open water, or a triathlon swim leg — one converter.
Swim Pace Calculator
Convert between total swim time and pace per 100m — for the pool, open water, or a triathlon swim leg.
Distance
Total Time
15:00
Pace / 100m
2:00
Pace / 100yd
1:50
About This Tool
Swimming is conventionally paced per 100m rather than per km like running or cycling, which makes it awkward to convert on the fly. This tool works both directions — enter a total time for a given distance to see your pace per 100m and per 100 yards, or enter a pace to see what it produces over a 750m sprint swim, a 1.9km 70.3 swim, or any custom distance.
How To Use It
- Choose "Time → Pace" if you know your total time for a set distance.
- Choose "Pace → Time" if you know your pace per 100m and want to see the total time it produces.
- Pick a preset distance (a common triathlon swim leg length) or enter a custom distance in meters.
- Results show pace per 100m and per 100 yards, since pool lengths and race listings use both.
Why swimmers count in hundreds
Runners think in minutes per kilometre or mile. Swimmers think in time per 100 metres, and once you are used to it the convention makes obvious sense — it is roughly the length of a hard effort you can hold in your head, and pool sets are built from it.
The conversion matters most when you are moving between a pool you know and an open-water race you do not. A 1:45 per 100m in a 25m pool and a 1:45 per 100m in a sea swim are very different levels of fitness, for reasons worth understanding before race day.
Pool pace is not open-water pace
Almost everybody swims slower in open water than their pool pace predicts, and the gap is larger for less experienced swimmers. The causes are all avoidable-ish, and none of them are fitness.
- No walls. Push-offs contribute a meaningful fraction of pool speed over a set, and in open water there are none at all.
- Sighting. Lifting your head to navigate costs time directly and disrupts body position for several strokes afterwards.
- Not swimming straight. A swimmer who drifts covers more distance than the course, and the drift is invisible from inside it.
- Chop, current and other swimmers, none of which exist in lane four on a Tuesday.
- The start, which in a mass swim is genuinely chaotic and rarely fast.
A working assumption
Plan on being slower in open water than your pool pace, and treat any improvement on that as a bonus. The way to close the gap is not more fitness — it is open-water practice, particularly sighting, which is a skill rather than a capacity.
What a wetsuit does to your pace
A wetsuit adds buoyancy, which lifts your legs and improves body position, which reduces drag. For most age-group swimmers that is worth a real amount of time — and it is worth more the worse your natural body position is, which means it flatters weaker swimmers more than strong ones.
The corollary catches people out in warm-water races where wetsuits are not permitted. If every open-water session you have done has been in neoprene, your first skins swim will feel dramatically harder and slower, and race day is the wrong moment to discover it.
Using a swim pace in a race plan
For a triathlon, the swim split matters less for the clock than for what state you arrive on the bike in. A swim that is 90 seconds quicker but leaves you gasping through T1 and unable to ride properly for ten minutes is not a faster race.
Set a swim pace you can hold while breathing comfortably, then build the rest of the race around it. The split calculator will show you how small a share of the total it actually represents.
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Frequently Asked Questions
What is a good swim pace for a triathlon?
Amateur triathletes commonly swim 1:45-2:30 per 100m in open water; competitive age-groupers are often under 1:30. Open water is typically slower than pool pace due to sighting, drafting limitations and lack of a wall push-off — use your own recent times as the more reliable guide.
How do I convert swim pace from meters to yards?
Multiply your per-100m pace by 0.9144 to get pace per 100 yards (a yard is shorter than a meter, so the per-100-unit time drops slightly). This calculator does the conversion for you automatically.
What is the swim distance in a 70.3 triathlon?
1.9km (1.2 miles). A Sprint distance swim is typically 750m, Olympic is 1.5km, and Full Distance (Ironman) is 3.8km — see the Triathlon Split Calculator for the full breakdown by category.
Why am I slower in open water than in the pool?
No walls to push off, sighting that costs time and disrupts body position, drifting off a straight line, plus chop, current and other swimmers. The gap is larger for less experienced swimmers, and it closes with open-water practice rather than with fitness — sighting in particular is a skill, not a capacity.
How much faster does a wetsuit make you?
Enough to matter for most age-groupers. A wetsuit adds buoyancy, which lifts the legs and improves body position, which cuts drag — so it flatters swimmers with poor natural body position most. The corollary is that if all your training has been in neoprene, a skins race will feel dramatically harder.
Should I swim as fast as possible in a triathlon?
No — not at the cost of the bike. The swim split matters less for the clock than what state you reach transition in: a swim 90 seconds quicker that leaves you unable to ride properly for the first ten minutes isn't a faster race overall. Swim at a pace you can hold while breathing comfortably, not at your absolute limit.