Work Experience Calculator

Why adding it up by hand goes wrong

Two things make this harder than it looks. The first is month lengths: from 31 January to 1 March is one month and one day in a non-leap year, and any calculation that treats a month as thirty days gets a different answer. The second is overlaps - two concurrent roles, or a start date that precedes the previous role's end date by a fortnight.

Both are handled explicitly here. Durations use real calendar months, and overlapping periods are either counted once or added together depending on which you choose, with the merged periods shown so you can see what was actually counted.

Merge or sum, and which one an application means

Merge counts overlapping time once. That is what a job application means by total years of experience, and it is the right default: holding two roles in one calendar year does not give you two years of experience. Sum adds them, which is defensible when the roles were genuinely separate commitments - two independent consulting contracts, for instance.

• Merge: overlapping periods counted once, with the union shown
• Sum: overlapping periods added together
• Gaps are never counted in either mode
• Ongoing roles resolve against an 'as of' date you can see and change
• Results in years, months and days, and in decimal years

Reproducible by design

A role marked as ongoing resolves against an explicit 'as of' date, which defaults to today but is a field you can see and edit. The calculation itself never reads your system clock, so the same inputs give the same answer on any machine in any timezone - and a screenshot of a result stays checkable.

All the date arithmetic is date-only, with no times and no timezones anywhere in it. That avoids a real and common bug: parsing a date string as UTC midnight and then reading it back in a local timezone can shift it by a day, which is enough to change the month total you type into an application.

What it will not do

It will not apply statutory definitions of experience. Some employers and some rules count a year only if a minimum number of days were worked, and seniority for benefits is sometimes computed differently again. This is calendar arithmetic, so check the specific requirement you are filling in.

It also does not decide whether internships, freelance work or part-time roles should count - that is your judgement, and we would rather say so than quietly include or exclude them. And it does not weight part-time roles by hours.