Sick Pay Shortfall Calculator

How the calculation works

Normal weekly earnings are estimated from the pay figure entered. Employer full-pay and half-pay periods are modelled first, because occupational sick pay is normally the total amount received rather than something paid on top of Statutory Sick Pay.

Statutory Sick Pay entitlement runs for up to 28 weeks from the start of the sickness absence, so employer sick pay counts within that period rather than delaying it. Once those 28 weeks have passed, no Statutory Sick Pay remains, even where employer sick pay continues.

Statutory Sick Pay can be offset against occupational sick pay, but it is not a deduction from it. While the entitlement lasts, the calculator does not model a week below the Statutory Sick Pay rate. Half pay that falls under that rate is therefore shown at the statutory amount instead, and reverts to the contractual half-pay figure only for weeks after the entitlement has expired.

For 2026/27, Statutory Sick Pay is the lower of £123.25 a week or 80% of average weekly earnings. Real payroll figures can differ, because Statutory Sick Pay uses qualifying days, average-earnings rules and the terms of a particular contract. Tax and National Insurance are not modelled, so every figure shown is gross.

Source: GOV.UK, Statutory Sick Pay — what you'll get. Rates last reviewed 2026-09-25.

Nothing entered here is sent anywhere. The calculation runs in your browser and no figures are stored, logged or added to the page address.

Do I need income protection if I get sick pay from work? explains what the shortfall means in practice, and income protection deferred periods explained covers the waiting period that sits alongside it.