How the 90 days work
Each time you enter the US on an ESTA, you are admitted for up to 90 days. The day you arrive counts as day 1, so you must leave by day 90. Your I-94 record at i94.cbp.dhs.gov shows your exact “admit until” date.
A side trip to Canada, Mexico or a nearby Caribbean island doesn’t give you a new 90 days. You come back on the rest of the original 90, and the days you spent outside the US still run. Tick “Came back from Canada, Mexico or the Caribbean” on a trip and the calculator keeps counting from your first entry.
Who it applies to
Citizens of the 40-plus Visa Waiver Program countries, such as the UK, most EU countries, Australia, New Zealand and Japan, travelling for tourism or business with an approved ESTA. See US rules by passport.
Questions
How long can I stay in the US on an ESTA?
Up to 90 days per entry under the Visa Waiver Program, counting the day you arrive as day 1. Your I-94 record shows the exact “admit until” date, and that date is the one that counts.
Does a trip to Canada or Mexico reset the 90 days?
No. If you go to Canada, Mexico or a nearby Caribbean island and come back, you are readmitted only for what is left of your original 90 days (8 CFR 217.3(b)). It can reset only if you live in the country you visited.
Is there a limit per year?
The law sets no fixed yearly limit. Border officers decide at every entry and can refuse you if your trips look like you live in the US, so leave real gaps between long stays.
Can I extend my stay?
No. Visa Waiver visitors can’t extend their stay or change status. Only an emergency can get you up to 30 extra days of “satisfactory departure”.
What happens if I overstay?
Even one day over ends your Visa Waiver eligibility: you’ll need a visa for every future trip to the US.
More free calculators: Schengen 90/180 calculator · UK Statutory Residence Test calculator · US substantial presence test calculator