Understanding Altitude Adjustments in Swim Times
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When swimmers compete at higher altitudes, the reduced oxygen levels can affect their performance, often resulting in slower times compared to those swum at sea level. To account for this, many organizations apply an altitude adjustment to the times, which compensates for the physiological effects of swimming at elevation.
For example, Swimcloud uses altitude settings from Hy-Tek meet result files to display both the swimmer's actual time and an altitude-adjusted time, marked with an "A" tag. This adjusted time provides a fairer comparison with performances at lower elevations.
Different organizations use slightly different conversion factors for these adjustments. For instance, the NCAA applies a 20-second adjustment to the 1,500-meter freestyle for meets held at altitudes between 4,251 and 6,500 feet. These adjustments ensure that athletes competing at higher altitudes are not at a disadvantage when their times are compared to those of swimmers who competed at sea level.
What's the Official Time?
It's important to note that the official time is always the actual time swum at the meet, not the altitude-adjusted time. The adjusted time is simply for comparison purposes and does not count for qualification or records.
Does Swim Standards show altitude-adjusted times?
Update (October 1, 2026): This answer below has changed. Swim Standards now shows altitude-adjusted times — see the updated answer underneath.
No, Swim Standards does not display altitude-adjusted times. We focus on showing actual meet times as recorded. Please note that we are not an official rankings platform.Yes. On a swimmer's meet results table, Swim Standards now shows an altitude-adjusted time alongside the as-swum time, whenever altitude data is available for that meet. You can choose which conversion table to apply — USA Swimming or NCAA — using the standards below.
As noted above, the adjusted time is not the official time. It's shown for reference and comparison only — it does not count for qualification, records, or anything official. For that same reason, Swim Standards does not factor altitude-adjusted times into our rankings; our rankings continue to use official as-swum times only.
One important limitation: we can only calculate an adjustment when the altitude is actually present in the meet data we have. This is typically set in a meet's Hy-Tek results file, but not every meet host configures it, and meet data pulled from other sources is sometimes missing it too. If altitude isn't available for a meet, no adjusted time is shown — we don't estimate or infer elevation from a pool's location or any other outside source. As more meet hosts include altitude in their results, coverage will naturally improve.
USA Swimming Altitude Adjustments
Source: USA Swimming Policy Manual (as of January 2013). Applies to meets held at 3,000 ft or above.
Event Distance 3,000–4,250 ft 4,251–6,500 ft Above 6,500 ft 200 0.50 sec 1.20 sec 1.60 sec 400 or 500 2.50 sec 5.00 sec 7.00 sec 800 Freestyle Relay 2.00 sec 4.80 sec 6.40 sec 800 or 1000 5.00 sec 10.00 sec 15.00 sec 1500 or 1650 11.00 sec 23.00 sec 32.50 sec
NCAA Altitude Conversions
Event Distance 3,000–4,250 ft 4,251–6,500 ft Above 6,500 ft 100 Yards/Meters (Individual) 0.00 sec 0.10 sec 0.15 sec 200 Yards/Meters (Individual) 0.50 sec 1.20 sec 1.60 sec 500 Yards / 400 Meters (Individual) 2.50 sec 5.00 sec 7.00 sec 1000 Yards / 800 Meters 6.30 sec 11.40 sec 18.50 sec 1650 Yards / 1500 Meters 11.00 sec 20.00 sec 32.50 sec
Side-by-Side Comparison
Where both standards cover the same event distance
Event Standard 3,000–4,250 ft 4,251–6,500 ft Above 6,500 ft 200 USA Swimming 0.50 sec 1.20 sec 1.60 sec 200 NCAA 0.50 sec 1.20 sec 1.60 sec 500/400 USA Swimming 2.50 sec 5.00 sec 7.00 sec 500/400 NCAA 2.50 sec 5.00 sec 7.00 sec 800/1000 USA Swimming 5.00 sec 10.00 sec 15.00 sec 800/1000 NCAA 6.30 sec 11.40 sec 18.50 sec 1500/1650 USA Swimming 11.00 sec 23.00 sec 32.50 sec 1500/1650 NCAA 11.00 sec 20.00 sec 32.50 sec
Key differences: The two standards diverge notably at the longer distances. For the 800/1000, NCAA adds significantly more time at moderate and high altitude (6.30 vs 5.00, and 18.50 vs 15.00). For the 1500/1650, they agree at the low and high tiers but NCAA applies less adjustment at mid-altitude (20.00 vs 23.00 sec). The 100 exists only in NCAA standards, and the 800 freestyle relay exists only in USA Swimming.
If you have any questions or thoughts on this, feel free to join the conversation below!
Last updated: October 1, 2026 — Added altitude-adjusted times to swimmer meet results tables (USA Swimming and NCAA conversion tables selectable), with the official-time and rankings policy clarified above. Altitude adjustment requires altitude data present in the meet's results file and is not applied to Swim Standards rankings.
