Critical Illness Cover Calculator

Estimate the right critical-illness lump-sum cover and annual premium for your situation.

Last reviewed: June 2026Built & maintained by RahulMethodology & sourcesResults are estimates for education only — not insurance or financial advice. Confirm cover and premiums with a licensed insurer or advisor.

How Much Critical Illness Cover Is Right?

A common rule of thumb is 3–5× annual income, plus enough to clear major debts and fund 12–24 months of recovery. Critical illness cover pays a tax-free lump sum on diagnosis of one of a defined list of serious illnesses, so the money can be used however you need it — treatment, mortgage payments, home modifications, or simply replacing lost income while you recover.

What drives the premium

What critical illness insurance pays for

Critical illness cover pays a lump sum on diagnosis of a covered serious condition — typically cancer (excluding most early-stage cancers), heart attack, stroke, multiple sclerosis, kidney failure, major organ transplant, coronary artery bypass, and a long list of less common conditions. The payout is yours to use however you want: replace income while you cannot work, pay for treatment not covered by health insurance, clear the mortgage, pay caregivers, or simply protect the family's standard of living during the recovery period. It is not health insurance — it pays cash, not medical bills.

How much cover is enough

A practical baseline is 12–24 months of household after-tax income, plus any outstanding short-term debt. Someone earning £45,000 net with a £200,000 mortgage might target £100,000–£150,000 of critical illness cover — enough to clear high-interest debt, fund 12 months of recovery without touching savings, and pay for treatment options not available on the NHS. Households with smaller emergency funds need more cover; households with substantial savings can carry less.

What changes the premium

Common pitfalls in claims

  1. Non-disclosure on application. Insurers verify medical records on claim. Anything material that was not disclosed — even unintentionally — can void the policy.
  2. Conditions excluded by definition. "Heart attack" requires specific diagnostic criteria (raised troponin, ECG changes, characteristic symptoms). A "minor cardiac event" or "near miss" usually does not qualify.
  3. Early-stage cancers excluded. Most policies exclude carcinoma in situ, early prostate cancer (Gleason ≤6, T1a/b), and basal/squamous cell skin cancers.
  4. Survival period. Most policies require the policyholder to survive 10–28 days after diagnosis for the claim to pay.

Stacking with other cover

Critical illness is most useful as a layer alongside (not replacing) life insurance and income protection. Life insurance pays on death; income protection pays a monthly benefit while you cannot work; critical illness pays a lump sum on diagnosis. The three solve different problems and most adults with dependants and a mortgage benefit from all three at appropriate levels.

Read the definitions, not the brochure. Two policies advertised as covering "cancer" can have wildly different exclusions. The policy wording, not the marketing summary, is what pays the claim.

Frequently Asked Questions

A policy that pays a tax-free lump sum if you are diagnosed with one of a defined list of serious conditions — typically cancer, heart attack, stroke, kidney failure, and major organ transplants.
A common rule is 3–5× your annual income, plus an allowance for outstanding mortgage and major dependent expenses.
Age is the biggest driver (premiums roughly double every 10 years after 35). Smoking status, gender, family history, and pre-existing conditions are next.
In most jurisdictions the lump sum paid out is tax-free. Premiums are generally paid from after-tax income.
Yes. Life insurance only pays on death; critical illness pays while you are still alive and unable to work. The two are complementary, not substitutes.