Hundred SummersIncome protection calculator: the gap, the cap and the deferred period
The most an insurer would cover, the monthly benefit that would hold your essential outgoings, and how many months your employer’s sick pay, Statutory Sick Pay and savings already carry you, which is the honest way to choose a deferred period. Your figures never leave your browser.
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Worked example
Computed when this page was built by the same engine that runs the calculator above, so the figures below and the live tool can never disagree. Change any input above to see your own.
| Inputs | |
|---|---|
| Salary | £40,000 |
| Essential outgoings a month | £1,800 |
| Employer sick pay | 3 months full, then 3 months half |
| Savings | £6,000 |
| Existing cover | None |
| Insurer cover limit | 60% |
| Results | |
|---|---|
| Take-home a month | £2,693 |
| Most an insurer would cover a month | £2,000 |
| Benefit that would cover essentials | £1,800 a month |
| Months your own resources last | 8 |
| Longest deferred period they reach | 6 months |
The next question
What would a serious illness cost us? →Critical illness cover calculator
Or answer it with everything else: the full Hundred Summers plan connects your pay, pensions, savings, property, tax and spending year by year, and stress-tests them across 500 simulated market histories.
Read the guide
- Income protection, critical illness or life cover: which risk are you actually insuring? →Three policies, three different events. The population odds of each before retirement, what each policy pays and when, why long absence is the risk most households are least covered for, and how sick pay and savings set the deferred period.
Why the cap matters
Insurers limit income protection to a share of gross pay, usually 50–65%, because a personal policy pays out tax-free and they do not want claiming to pay better than working. For most earners 60% of gross is close to full take-home, so the cap rarely bites; it does for lower earners with high fixed costs, and the calculator shows the shortfall when it does. Benefit is also reduced by continuing sick pay and some state benefits, and an own occupation definition pays far more reliably than any occupation.
Reading the deferred-period menu
The deferred period is the biggest lever on the premium. Rather than picking one from the list, count your runway: full pay, then half pay, then Statutory Sick Pay (since 6 April 2026 the lower of £123.25 a week and 80% of your average earnings, from the first day of sickness) for what remains of its 28 weeks, with savings filling each month’s gap against essentials. A deferred period no longer than that runway means paying only for the risk you cannot carry yourself. The risk reality calculator shows how likely a two-month absence is before retirement; the Hundred Summers app’s income-protection what-if applies the shock to your whole plan; the life insurance calculator sizes the other half of the protection question.
Sources
- Statutory Sick Pay: gov.uk; the April 2026 changes (day-one entitlement, 80%-of-earnings floor) from Acas.
- Income tax and National Insurance: HMRC Income Tax rates and National Insurance rates.
- The 50–65% cover ceiling is common insurer practice (each insurer publishes its own maximum benefit rules); it is a parameter you can change above.