Who Owns It

Royal Yachting  Association

Why Did It Start

Originally introduced in Britain in the 1940’s, the RYA developed and evolved the system over time.  Starting in 2009 the RYA launched PY Online, the web-based tool to calculate and update the Portsmouth Numbers. During the Summer of 2020 US Sailing and the RYA partnered to bring PY Online to US Sailing Member clubs and sailors. It is primarily used for rating smaller boats, including catamarans.

How It Works

Using the US Tables of ratings for known classes, clubs run and score races using the simple time on time formula of (Elapsed Time/PY Number) * 1000 = Corrected time.  Clubs then submit these results to PY Online where the platform automatically evaluates the results and suggets rating adjustments.  Individual clubs then decide to update the numbers for local sailing. Annually US Sailing will update the US Tables for classes based upon the results and PY numbers used locally.

Who Uses It

US Sailing Member Clubs to rate centerboard boats, smaller keelboats, and multihulls, Portsmouth Yardstick is used for local fleet races around the country.

Where We Fit In

US Sailing works with the RYA to ensure access and help with the local adminstration of the PY system for US Clubs.

What’s Required

Your local club must be a member of US Sailing. We ask that all timed race results be submitted via the PY Online portal.


The Portsmouth Yardstick relies on accurate reports of race results from clubs like yours. Sign your club up today!


Access to all Portsmouth Yardstick handicapping tables is free to all sailors.

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