FTE Calculator — Hours to Full-Time Equivalent

The arithmetic is simple; the interpretation is not

Full-time equivalent is a ratio: total paid hours divided by the standard full-time hours for the period. At the tool's default baseline of 2,080 hours a year — 40 hours across 52 weeks — someone working 1,040 hours is 1040 ÷ 2080 = 0.5 FTE, and two such people sum to 1.0.

The baseline is a choice, not a fact, and this matters more than it first appears. A 37.5-hour standard week gives 1,950 hours a year, so identical staff produce a different FTE figure depending purely on which convention the organisation uses. Any comparison between organisations is meaningless without knowing both baselines — which is why the tool lets you set it rather than fixing it.

FTE normalises headcount; it does not measure work

Here is the limitation that matters: FTE counts contracted paid hours, not capacity or output.

Two people at half time equal one FTE and are emphatically not one person. There are two people to brief, two sets of context to maintain, two calendars to align, and communication between them that a single person would not need. Run it the other way and the metric misleads in the opposite direction — two half-time specialists may cover ground that one full-time generalist cannot.

The metric is silent on all of this by design. That silence is exactly what makes it a good normalisation device for budgeting and reporting, and exactly what makes it useless for predicting what a team will deliver.

Where FTE genuinely works

It is the right tool for comparing team sizes across mixed working patterns, for headcount budgeting, for reporting to funders or regulators who mandate a standardised figure, and for per-employee ratios that part-time staff would otherwise distort.

A team of three full-timers and four half-timers has a headcount of 7 and an FTE of 5. Both numbers are true and both are needed — headcount for anything that attaches to a person, FTE for anything that attaches to hours.

The per-person overhead FTE cannot see

Which leads to the practical gap. Some costs attach to a person rather than to an hour: a laptop, a software seat, onboarding time, a share of a manager's attention. Two half-time staff incur those twice while registering as the same 1.0 FTE as one full-timer.

An FTE-based budget therefore understates the cost of a part-time-heavy team, sometimes substantially. The fix is not to abandon FTE but to carry a separate per-head overhead figure alongside it.

FTE is contracted hours, not available hours

It deducts nothing for holiday, sick leave, public holidays or training, because those are not what it measures. A team of 10 FTE does not deliver 10 person-years of work in a year — after leave and non-productive time it delivers meaningfully less.

If what you need is available capacity rather than contracted headcount, that is a different calculation entirely; the team capacity planner handles leave and overhead. Note too that some prescribed regulatory definitions of FTE do deduct leave, so check the one you are reporting against.

Overtime and the 1.0 cap

Whether hours beyond the standard week push someone above 1.0 FTE depends entirely on the convention you are reporting under. Many definitions cap an individual at 1.0 regardless of hours worked, particularly for government and funder reporting; others let it float.

The tool accepts any baseline and any hours, so it will follow whichever you need — but it does not enforce a cap, so check your reporting requirement rather than assuming. This is general business information rather than authoritative guidance: where a regulator or funder prescribes an FTE definition, that definition takes precedence over any general calculation.