What this calculator is for
This tool ranks a mixed fleet of different boat classes on level terms, using the Portsmouth Yardstick corrected-time formula: elapsed time × 1000 ÷ Portsmouth Number. Add every boat that raced, with its class, sail number, and elapsed time, and the table sorts the fleet by corrected time so the actual race winner is clear even when a Laser and a Wayfarer cross the line minutes apart.
It works as a standalone Portsmouth Yardstick handicap calculator for any single race: a club point-scoring evening, an open meeting, a training-week regatta, or a one-off pursuit-style fun race scored by handicap. There's nothing to install and nothing to sign up for; the current PY numbers are already loaded, so you can go straight from finish times to a results sheet.
For example, a Laser with a PN of 1100 sails the course in 44 minutes (2,640 seconds). Corrected time = 2,640 × 1000 ÷ 1100 = 2,400 seconds, or 40 minutes exactly. That's the number each boat gets ranked on, so a Laser and a much slower boat can finish minutes apart on the water and still be scored fairly against each other. See the corrected time formula page for how the calculation works in full, including tied results.
Portsmouth Numbers are pre-loaded from the current national RYA PY number list, so there's nothing to look up or type in by hand. The list is maintained by the Royal Yachting Association, which publishes an updated set of numbers each year based on race returns from clubs across the country.
Scoring a whole season rather than one race? The free Portsmouth Yardstick scoring spreadsheet carries results across race days and adds series points with a discard, or set up your club on Sailboat Racing for free and publish results the moment a race finishes.
Frequently asked questions
What is a good Portsmouth Yardstick number?
There's no such thing as a good or bad PN in isolation: a Portsmouth Number only has meaning relative to other classes, and a lower number always means a faster boat. A PN is working well for your fleet when it produces close racing across classes; if one class is consistently winning or losing by a wide margin, a club can apply its own local adjustment.
How is a Portsmouth Yardstick number calculated?
The RYA derives each class's PN from real race returns submitted by clubs across the country, so the numbers reflect actual results rather than a theoretical calculation. See how the Portsmouth Yardstick works for the full picture, including where the numbers come from and who sets them.
What's the difference between PY and PHRF/IRC?
PY is a single national handicap set by the RYA and applied to a class as published, with no measurement of an individual boat involved. PHRF, used mainly in North America, is assigned locally by one of around 40 regional authorities based on observed performance, so the same class can carry different PHRF numbers in different areas. IRC is a measurement-based rating rule calculated from a boat's physical dimensions rather than its race results, issued only by the RORC Rating Office or the UNCL in Paris.
What changed in the 2025 PY formula update?
In 2025 the RYA made its biggest change to the PY calculation in 30 years, working with Sheffield Hallam University. The method for finding each class's average corrected time switched from the mean to the median, so a handful of outlier results can no longer skew a class's number, and the qualifying time threshold was widened from 105% to 110% of the fastest corrected time, bringing more race returns into the calculation.
Do I need to enter elapsed time or corrected time?
Elapsed time, the raw time on your stopwatch from start to finish. This calculator applies the Portsmouth Number for you and works out each boat's corrected time automatically.