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Critical Illness Cover Calculator

Work out how big a critical illness lump sum you actually need. Enter your income, debts, expected treatment costs and any cover you already have, then press Calculate to see your gap.

Written by TopicDrill Editorial Team·Updated June 2026

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Your situation

Fill in the details, then press Calculate.

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Cover you should buy

$371,000

Total cover need$421,000
Income replacement$180,000
Debt + treatment + buffer$241,000

Where the cover goes

$421.0ktotal need
  • Income replacement$180,000
  • Expense buffer$36,000
  • Debt clearing$180,000
  • Treatment costs$25,000

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How the critical illness calculator works

A serious diagnosis hits your finances from several directions at once. You may stop earning while you recover, yet the mortgage, loans and weekly bills keep arriving, and treatment can add costs your health plan does not fully cover. This tool adds those pressures into one target lump sum so a single payout can carry you through.

The donut splits that target into four parts: the income you want to replace, a twelve month buffer for everyday expenses, the debts you would clear, and your treatment costs. The headline figure is what is left after subtracting cover you already hold, so it is the amount you would actually shop for.

A worked example

Suppose you earn $60,000 and want three years of income while you recover, spend $3,000 a month on household bills, owe $180,000 on a mortgage and expect $25,000 of treatment costs. The total need comes to about $421,000. If you already hold $50,000 of cover, the calculator shows a remaining gap of roughly $371,000 to insure.

Things to keep in mind

Policies differ on which conditions they pay out for, so always read the list of covered illnesses and the severity definitions before you buy. For an overview of how this protection works, see the Investopedia guide to critical illness insurance. If you also want to size up a death benefit for your family, pair this with our life insurance calculator.

Frequently asked questions

What is critical illness cover?

Critical illness cover is an insurance policy that pays a tax free lump sum if you are diagnosed with one of the serious conditions listed in the plan, such as cancer, a heart attack or a stroke. The money is yours to spend on anything, from replacing lost income to adapting your home.

How much critical illness cover do I need?

A common approach is to add up the income you would need to replace while you recover, the debts you would want cleared, any out of pocket treatment costs and a buffer for everyday bills, then subtract cover you already have. This calculator does that sum and shows the remaining gap.

Is critical illness cover the same as life insurance?

No. Life insurance pays out when you die, while critical illness cover pays out while you are still living but seriously ill. Some policies combine the two, but a combined plan usually pays only once, so read the terms before assuming you are covered for both.

Why subtract existing cover from the total?

Many people already hold some protection through an employer scheme or an older policy. Counting that existing cover means you only buy the shortfall, which keeps your premiums lower while still closing the gap between what you have and what you would need.

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