Bike Helmet Replacement Calculator
The quick answer is well known: most makers say 3–5 years, and always after a crash. What that misses is your helmet — how it's used, where it lives, and what shape it's in. Answer five quick questions and get a replace-by recommendation with the reasoning shown. Everything runs in your browser — nothing is uploaded.
Been in a crash, or hit the ground hard? Replace it — no calculator needed. The foam liner (EPS) crushes to absorb one impact and doesn't recover, and the damage is usually invisible from the outside. Everything below only applies to a helmet that has never taken a hit.
About your helmet
Heat and UV matter: a helmet stored in a hot car or a sun-baked shed degrades faster than one kept indoors, so storage shortens the recommendation below.
Visible signs of wear
Any one of these means the helmet is done, whatever its age. Take the pads out and check the foam in good light.
Result
This tool can never certify a helmet as safe. If your helmet's sticker or manual gives a replacement interval or date, that overrides everything here — and a crash means replace, whatever the age or the answer above. Not safety advice.
Do bike helmets actually expire?
Not officially. The CPSC — the US safety standard every bike helmet sold here must meet — sets no expiration rule, and we'd rather say that plainly than invent one. What does exist is manufacturer and test-lab guidance: Bell and Giro recommend replacing a helmet roughly every 3 years of use, the industry convention is 3–5 years, and the Snell Foundation recommends 5 years, citing UV, sweat, and adhesive degradation. This calculator turns those conventions plus your storage and usage into one recommendation — your helmet's own sticker or manual overrides it.
Why replace after a crash if it looks fine?
The protective part is a one-use crushable foam (EPS). In an impact it compresses permanently to absorb energy — it doesn't bounce back, and the shell usually hides the damage. A crashed helmet can look perfect and protect like a stale cracker, which is why every manufacturer and test lab says the same thing: crash it, replace it.
Is this official guidance?
No. It summarizes publicly stated replacement conventions from manufacturers and test labs; it is not safety advice and never certifies a helmet. For authoritative guidance see the CPSC's helmet guide and the Bicycle Helmet Safety Institute on replacement, and check your helmet maker's website for your exact model.
Does my data get uploaded?
No. The page is fully client-side; nothing you enter leaves your browser.