JoulesCalc › UK Limit

UK Airsoft FPS & Joule Limit

The legal energy caps for airsoft in the United Kingdom, converted to FPS for every BB weight.

UK law defines airsoft limits in joules, not FPS: 1.3 J for guns capable of fully automatic fire, and 2.5 J for single-shot (bolt-action) replicas. Exceed those and the replica can legally be treated as a firearm — a serious criminal matter.

Limits by BB weight

BB weight1.3 J (full-auto max)2.5 J (single-shot max)
0.20g377 FPS519 FPS
0.25g337 FPS464 FPS
0.28g319 FPS438 FPS
0.30g308 FPS424 FPS
0.32g298 FPS410 FPS
0.36g281 FPS387 FPS
0.40g267 FPS367 FPS
0.43g257 FPS354 FPS
0.48g243 FPS335 FPS
⚠️ Site rules are usually stricter than the law — most UK sites cap AEGs at 350 FPS/0.20g and snipers at ~2.3 J with minimum engagement distances. Always follow the site's rule sheet. This page is general information, not legal advice.

FAQ

What is the legal airsoft limit in the UK?
Under the Policing and Crime Act 2017 (amending the VCR Act 2006 framework), an airsoft gun capable of firing above 1.3 joules (fully automatic) or 2.5 joules (single-shot only) is no longer a legal airsoft weapon and may be classified as a firearm. Most UK sites enforce 1.14J–1.3J for AEGs.
What FPS is 1.3 joules on a 0.20g BB?
About 373 FPS. Many UK sites round down to 350 FPS on 0.20g for full-auto AEGs to keep a safety margin.
Do UK rules account for joule creep?
Yes in principle — the legal limit is defined in joules regardless of BB weight, so a gun that creeps above 1.3J on heavy BBs while shooting full-auto is over the limit even if it chronos under 373 FPS on 0.20g.
Check your gun against the UK limit — calculator
Field limitsFPS chartJoule creep