Emergency Fund Calculator

An emergency fund is money set aside to cover unexpected costs or a gap in income, without having to rely on credit cards or loans. This calculator helps you work out a sensible target based on your essential monthly spending, and how long it might take to get there.

How to use the emergency fund calculator

Enter your monthly essential expenses, choose how many months of cover you want to aim for, and enter any savings you already have set aside. Add how much you can realistically save each month, and the calculator shows your target fund size, how much more you need, and roughly how long it will take to get there.

How the calculation works

Your target fund size is simply your monthly essential expenses multiplied by the number of months of cover you choose. The calculator subtracts any savings you already have to find your remaining shortfall, then divides that shortfall by your monthly saving amount to estimate how many months it will take to reach your target.

Worked example

Say your essential monthly expenses come to £1,500, and you are aiming for 3 months of cover, giving a target of £4,500. If you already have £1,000 saved, your shortfall is £3,500. Saving £150 a month, it would take roughly 24 months, about two years, to reach your full target.

Choosing how many months to aim for

Three months tends to suit people with stable employment and no dependants, while six months or more may feel more appropriate if your income is irregular, you are self-employed, or you have a family relying on you financially. There is no single right answer, and building up gradually towards a bigger target is perfectly reasonable if six months feels out of reach right now.

Common mistakes people make

A common mistake is including non-essential spending in the target calculation, which inflates the goal beyond what you would actually need to cover in a genuine emergency. Another mistake is keeping the fund somewhere hard to access quickly, such as a fixed-term bond, which defeats the purpose of having it available at short notice. It also helps to top the fund back up after using it, rather than treating it as a one-off target you never revisit.

Related calculators

Once your emergency fund is on track, our savings goal calculator can help with other targets, and our compound interest calculator shows how your savings could grow over time. If you are also managing debt, our debt payoff calculator can help you plan alongside your emergency fund, and our ISA calculator is useful once you are ready to save tax-efficiently beyond your emergency fund.