Do I need a tetanus shot for this cut?

The rule of thumb: clean minor wounds need a booster if your last was over ten years ago; dirty, deep or puncture wounds, anything with soil, rust, animal contact or crush damage, shorten that to five years.

Nobody remembers their date, which is itself the answer: uncertain counts as due. The booster works best within days of injury.

Clean any wound under running water first regardless. Deep punctures, bites, heavily soiled wounds and wounds in people never fully vaccinated deserve medical review beyond the shot itself; tetanus is rare precisely because boosters are boring and effective.