Pay & Tax

Unpaid Leave Calculator

What time off without pay actually costs you.

What it does. Unpaid leave costs less than the gross figure suggests, because the pay you lose would have been taxed. Losing a month of a £48,000 salary is £4,000 gross but a smaller amount of take-home — and in a cumulative tax system, some of the tax already paid comes back through the year.

Runs in your browserNothing uploadsNo signupWorks offline

How to use Unpaid Leave Calculator

Enter your salary and how much unpaid leave you are taking.
Set your tax and pension assumptions.
Compare gross cost against real take-home cost.

The gross figure overstates the cost

A month of unpaid leave on a £48,000 salary removes £4,000 of gross pay. What you actually lose is the net of that — the tax and national insurance that would have been deducted are not paid either.

Depending on the band, the real cost is commonly 60–75% of the gross figure.

In the UK, PAYE is cumulative: a month at zero pay means the personal allowance for that month is unused, and the system typically refunds some tax in later months. That refund is part of the true cost calculation and is routinely forgotten.

What it does affect beyond pay

Pension contributions stop for the period, employer’s included — often the largest hidden cost.
Accrual of holiday may pause, depending on the arrangement.
Statutory payments such as maternity or sick pay can depend on recent earnings.
Benefit and credit thresholds use annual income, which a period of unpaid leave lowers.
Mortgage affordability assessments look at recent payslips.

The pension one deserves the most attention. A missed employer contribution is money that was available and is not recoverable, and over a long break it compounds for the rest of your working life.

Alternatives worth pricing first

Unpaid leave is one option among several, and the others often cost less.

Reduced hours for a longer period, using accrued holiday, a formal sabbatical policy, or averaging pay across the year through a salary-averaging arrangement can all achieve the same time off at lower net cost.

Price them all before deciding. The differences are frequently larger than people expect, particularly where a pension contribution can be maintained.

Frequently asked questions

How much does unpaid leave actually cost?

Commonly 60–75% of the gross figure, because the pay you lose would have been taxed. A month off a £48,000 salary is £4,000 gross but less in take-home terms.

Will I get any tax back?

In a cumulative PAYE system such as the UK, usually yes. A month at zero pay leaves that month’s personal allowance unused and the system typically refunds some tax in later months.

Does unpaid leave affect my pension?

Yes, and this is often the largest hidden cost. Contributions stop for the period, including the employer’s, and a missed employer contribution is not recoverable.

Does it affect statutory maternity or sick pay?

It can. Those payments are often calculated from recent earnings, so a period of unpaid leave in the reference window can reduce them. Check the qualifying period before booking leave.

Is there a cheaper way to take time off?

Often. Reduced hours over a longer period, accrued holiday, a formal sabbatical policy or a salary-averaging arrangement can achieve the same break at lower net cost — particularly where pension contributions continue.