A swim time converter turns a result swum in one pool into its equivalent in another, so a 25-yard time can be compared fairly with a 25-metre or 50-metre time. The calculator on this page applies the standard course-conversion factors used across club, college and masters swimming to move a time between short course yards (SCY), short course metres (SCM) and long course metres (LCM). Below you will find the exact formulas, a conversion factor chart, worked examples and answers to the questions swimmers ask most.
Clinical Tools Library · Sports & exercise
Swim Time Converter — SCY · SCM · LCM
Convert a race time between a 25-yard, 25-metre and 50-metre pool using the standard course-conversion factors, and see exactly where every hundredth of the difference comes from.
Converted time
—
Confirm the race details to calculate.
Estimate — not an official time
Where the difference comes from
Each lane is drawn to scale. The gold bars are walls: every wall is a push-off, and a push-off is faster than swimming.
The maths, shown
Independent check & race detail
- Status
- —
Even-pace splits in the target course
| Segment | Cumulative | Segment time |
|---|---|---|
| — | ||
Distance factors
| Conversion | Factor | Notes |
|---|---|---|
| SCY ↔ SCM, 50–200 | 1.11 | Distance only; wall count is identical |
| SCY ↔ LCM, most events | 1.11 | Increment applied for 50–400 |
| 500 y ↔ 400 m, 1000 y ↔ 800 m (LCM) | 0.8925 | No increment |
| 1650 y ↔ 1500 m (LCM) | 1.02 | No increment |
| 500 y ↔ 400 m, 1000 y ↔ 800 m (SCM) | 0.875 | Pure distance ratio; same walls |
| 1650 y ↔ 1500 m (SCM) | 0.997 | Pure distance ratio; same walls |
| SCM ↔ LCM | 1.00 | Distance unchanged; increment only |
Turn increment by stroke
| Stroke | Per wall | 50 | 100 | 200 | 400 |
|---|---|---|---|---|---|
| Backstroke | 0.60 | 0.60 | 1.20 | 2.40 | — |
| Butterfly | 0.70 | 0.70 | 1.40 | 2.80 | — |
| Freestyle | 0.80 | 0.80 | 1.60 | 3.20 | 6.40 |
| Individual medley | 0.80 | — | 1.60 | 3.20 | 6.40 |
| Breaststroke | 1.00 | 1.00 | 2.00 | 4.00 | — |
Distance events (500 y / 1000 y / 1650 y ↔ 400 m / 800 m / 1500 m) carry no turn increment between SCY and LCM: the factor already absorbs it. Between SCM and LCM the increment is fixed at 6.40 s (400), 12.80 s (800) and 24.00 s (1500).
Not applied here: altitude adjustment. Some timing systems add an altitude correction for distance events swum above roughly 300 m elevation. If your governing body requires one, apply it separately.
Exact distance conversions
One yard is exactly 0.9144 m. Nothing about this is an estimate — only the time conversion is.
| Yards | Metres | Metres | Yards |
|---|---|---|---|
| 25 y | 22.86 | 25 m | 27.34 |
| 50 y | 45.72 | 50 m | 54.68 |
| 100 y | 91.44 | 100 m | 109.36 |
| 200 y | 182.88 | 200 m | 218.72 |
| 500 y | 457.20 | 400 m | 437.45 |
| 1000 y | 914.40 | 750 m | 820.21 |
| 1650 y | 1508.76 | 1500 m | 1640.42 |
| 1760 y (1 mile) | 1609.34 | 1609.34 m (1 mile) | 1760.00 |
Neither the 1650-yard nor the 1500-metre freestyle is a mile. Both are shorter.
The single most common error
Reading a 25-metre time as a 25-yard time (or the reverse) is the mistake that produces impossible entry times. The pools look the same. They are not.
| If the time was swum in… | Its LCM equivalent |
|---|---|
| Enter a confirmed short-course time to populate this table. | |
A 25 m lap is 2.14 m longer than a 25 y lap — 8.6% more water per length, and no extra wall to help you.
Method
This tool implements the course-conversion model used by the timing and team-management software that clubs actually run (Hy-Tek / Colorado Timing lineage): the time is multiplied by a distance factor, then a per-wall increment is added when walls are lost or subtracted when walls are gained. Times are handled internally in hundredths of a second and rounded once, at the end.
Both directions are computed from the same constants, so converting a time out and back returns the original within one hundredth. That round trip is displayed as the independent check.
Sources
- Course conversion factors and per-stroke increments — SportsEngine Motion: How to perform course conversion / factoring of times
- Converted times are not official times — USA Swimming, Times and Recognition Policy Manual (PDF)
- Official results and time standards — USA Swimming Times
- Pool dimensions and course definitions — World Aquatics Competition Regulations and World Aquatics swimming rules
- Contribution of starts and turns to race time; short-course races average several per cent faster than the same long-course event — Born et al., section analyses of short-course individual medley (PMC9157519) and Born et al., turn performance in top-elite swimmers (PMC8472918)
Limits
- Conversion factors are population averages. A swimmer with an exceptional underwater kick loses more than average when walls are removed; a distance freestyler may lose almost nothing.
- Governing bodies use different tables. The NCAA, World Aquatics points and individual LSCs may not produce the figure shown here.
- The 100 individual medley does not exist as a long-course event, and the 50 m stroke events are not part of every championship programme. The tool stops rather than inventing a conversion.
- No altitude correction is applied.
Last reviewed: July 2026 · Next review due: July 2027 · Published by clinicaltoolslibrary.com
Full disclaimer, scope and how to report an error
This calculator is an educational reference and decision aid published by clinicaltoolslibrary.com. It is not medical advice, coaching advice, or an official timing service, and it does not tell you whether to train, compete, or enter a meet. Its output depends entirely on the values you enter; a wrong course or distance produces a confidently wrong answer.
Converted times have no official standing. Under USA Swimming's Times and Recognition Policy Manual, a time ceases to be official once it is converted from one course to another. Records, rankings, time standards and qualification are always assessed in the course actually swum. Meet hosts may accept converted times for entry and seeding at their discretion — read the meet information sheet.
Swimming carries physical risk. Nothing here should be used to justify training or racing against medical advice. If you have a health condition affecting exercise tolerance, speak to your clinician.
Found an error? Report calculation or reference errors to clinicaltoolslibrary.com via the site contact page so the figure can be checked against source and corrected. Errors in a medical device or a medicine — not in this tool — should be reported to your national regulator: in the United States, the FDA's MedWatch programme; in the United Kingdom, the MHRA Yellow Card scheme; in the EU, your national competent authority.
Printed from clinicaltoolslibrary.com — Swim Time Converter. Verify all figures against current source material before use.
Last reviewed July 2026 · Educational reference · A converted time is an estimate, never an official result.
How the swim time converter works
Every conversion answers two separate questions at once. First, how far apart are the distances? A 25-yard lap is 22.86 m, so a 100-yard race covers 91.44 m rather than 100 m. Second, how much free speed came from the walls? Push-off velocity after a turn is roughly 3 m/s against a free-swimming speed of about 1.4 m/s, so a swimmer who gets more walls gets more time for nothing. A reliable swim time converter handles both effects — a single flat percentage does not.
The swim time converter above uses the widely adopted model implemented in Hy-Tek and Colorado Timing software and applied by most club team databases, multiplies the time by a distance factor and then adds or subtracts an increment for each wall. It is documented in the SportsEngine Motion course-factoring reference that most club administrators work from.
Converting SCY to LCM and SCM
Multiply, then add the increment: converted time = (SCY time × factor) + increment. For SCY to SCM the increment is zero, because the wall count is identical and only the lap length changes. For SCY to LCM the increment restores the seconds gained from the extra turns.
Converting LCM to SCY (and back to SCM)
Run the same arithmetic in reverse: SCY time = (LCM time − increment) ÷ factor. Converting long course to short course always produces a faster number, which is why long course to short course conversion is popular in the autumn when swimmers move indoors.
Converting SCM to SCY and SCM to LCM
SCM to SCY is a pure distance conversion — divide by 1.11. SCM to LCM keeps the metric distance and only adds the increment for the walls that disappear, which works out at roughly two to three per cent on most events.
Swim time conversion factors chart
These are the factors and increments the swim time converter applies. Times are handled in hundredths of a second; the increments below are shown in seconds.
| Conversion | Factor | Notes |
|---|---|---|
| SCY ↔ SCM | 1.11 | No turn increment; wall count is the same |
| SCY ↔ LCM (most events) | 1.11 | Turn increment applied for 50 to 400 |
| 500 y ↔ 400 m, 1000 y ↔ 800 m | 0.8925 | No increment (except 400/500 medley) |
| 1650 y ↔ 1500 m | 1.02 | No increment |
| SCM ↔ LCM | 1.00 | Increment only; the distance is unchanged |
Turn increments by stroke
| Stroke | Per wall | 50 | 100 | 200 | 400 |
|---|---|---|---|---|---|
| Backstroke | 0.60 s | 0.60 | 1.20 | 2.40 | 4.80 |
| Butterfly | 0.70 s | 0.70 | 1.40 | 2.80 | 5.60 |
| Freestyle | 0.80 s | 0.80 | 1.60 | 3.20 | 6.40 |
| Individual medley | 0.80 s | — | 1.60 | 3.20 | 6.40 |
| Breaststroke | 1.00 s | 1.00 | 2.00 | 4.00 | 8.00 |
Worked swim time conversion examples
- 100 free, 50.00 SCY → LCM: (50.00 × 1.11) + 1.60 = 57.10
- 200 breast, 2:20.00 SCY → LCM: (140.00 × 1.11) + 4.00 = 159.40 = 2:39.40
- 500 free, 5:00.00 SCY → 400 LCM: 300.00 × 0.8925 = 267.75 = 4:27.75
- 100 free, 1:00.00 SCM → LCM: 60.00 + 1.60 = 1:01.60
- 100 back, 1:05.00 LCM → SCY: (65.00 − 1.20) ÷ 1.11 = 57.48
SCY, SCM and LCM: what the three courses mean
SCY is a 25-yard pool, used almost exclusively in the United States for high school, NCAA and winter club meets. SCM is a 25-metre pool, the standard short course internationally and the format of the World Aquatics Swimming Championships (25m). LCM is the 50-metre Olympic pool, the only course recognised for Olympic and World Championship long course records. The pool specifications for each are set out in the World Aquatics Competition Regulations, with the stroke and turn rules published alongside them in the World Aquatics swimming rules.
Where each course is used
- SCY — US high school, NCAA, US club winter season, US Masters.
- SCM — European and international winter season, short course world records.
- LCM — Olympic Games, World Championships, US club summer season.
Yards to metres swim conversions
Distance conversion is exact: one yard is 0.9144 m. That fixed relationship is what the 1.11 factor is derived from (1 ÷ 0.9144 = 1.0936, with the balance covering the extra wall in a metre pool over the same nominal distance).
| Yards | Metres | Metres | Yards |
|---|---|---|---|
| 25 y | 22.86 m | 25 m | 27.34 y |
| 50 y | 45.72 m | 50 m | 54.68 y |
| 100 y | 91.44 m | 100 m | 109.36 y |
| 500 y | 457.20 m | 400 m | 437.45 y |
| 1000 y | 914.40 m | 750 m | 820.21 y |
| 1650 y | 1508.76 m | 1500 m | 1640.42 y |
Note the trap in the second half of the table: 25 yards is not 25 metres, so a “100” in a yards pool is nearly nine metres shorter than a “100” in a metres pool. Any yards-to-metres swimming conversion that ignores this will flatter the swimmer.
Why short course times are faster than long course
The walls are the answer. Each turn gives a push-off and an underwater phase considerably faster than surface swimming, and a 25-metre pool provides twice as many of them as a 50-metre pool over the same distance. Race-analysis research on elite short course finals reports that start and turn sections together can account for a large share of total race time — in some events the turn sections alone exceed half of it — and that short course races average several per cent faster than the same event long course. That is also why turn performance discriminates so strongly between elite swimmers in short course racing.
It follows that no swim time converter is exact for an individual. A swimmer with a powerful underwater dolphin kick loses more than average when the walls are taken away; a pure distance freestyler may lose almost nothing. Treat a converted time as a planning number, and check your own history in both courses when you have it.
Converted times are not official times. USA Swimming’s Times and Recognition Policy Manual states plainly that a time is not official once it has been converted from one course to another. Converted times are used for seeding and entry where the meet host permits them; records, rankings and time standards are course-specific. You can look up your official results in the USA Swimming times database. Confirm the rules of your meet before entering a converted time.
Swim time converter FAQ
How accurate is a swim time converter?
A swim time converter is accurate enough for seeding, goal-setting and recruiting comparisons, typically within one to two per cent for most swimmers. It is a population average, not a prediction of your race. Turn ability, underwater kick and taper all shift the real result.
Can I use a converted time to enter a meet?
Often yes for entry and seeding, but never as an official time. Many meet hosts accept converted entries when a swimmer has no time in the meet’s course; records, rankings and qualifying standards are always judged in the course actually swum. Check the meet information sheet.
Why are short course times faster than long course?
Because a shorter pool means more turns, and each turn provides a push-off and underwater phase faster than surface swimming. Over 200 metres a swimmer gets three turns in a 50-metre pool and seven in a 25-metre pool.
How many metres are in a mile swim?
A true statute mile is 1,609.34 metres, or 1,760 yards. Swimmers rarely race it: the “mile” in a yards pool is the 1650-yard freestyle (1,508.76 m) and in a metres pool it is the 1500-metre freestyle. Both are shorter than an actual mile.
Is 25 yards the same as 25 metres?
No. 25 yards is 22.86 metres, about 8.5 per cent shorter. A 25-metre lap is 2.14 metres longer than a 25-yard lap, which is the single largest reason SCY times look faster than SCM times.
How do I convert long course to short course?
Subtract the stroke’s turn increment for the distance, then divide by the factor: SCY time = (LCM time − increment) ÷ 1.11. For LCM to SCM, simply subtract the increment; the distance does not change.
Do all strokes convert the same way?
No. The distance factor is shared, but the per-wall increment differs: 0.60 s for backstroke, 0.70 s butterfly, 0.80 s freestyle and individual medley, and 1.00 s for breaststroke. Breaststroke therefore loses the most when the walls disappear.
Related swimming calculators
Pair the swim time converter above with the swim pace calculator to turn a converted target into a per-100 pace, the swimming split calculator to build even or descending splits from it, and the swim lap calculator to count laps for any distance in a 25-yard, 25-metre or 50-metre pool. For competition-standard comparisons across events, use the swimming points calculator.
This page is an educational reference published by clinicaltoolslibrary.com. It is not coaching, medical or performance advice. Conversion factors reflect the standard model in common use and may differ from the factors your governing body applies; verify any figure that affects an entry, qualification or record before relying on it.
