Understand the level of risk first
This calculator is for educational purposes only and designed to give you an estimate. Investing offers the potential for better returns than cash savings over the long term (5+ years). But there are risks, the value of your investments may go down as well as up, and you may get back less than you’ve paid in. ISA tax benefits are based on personal circumstances and are subject to change.
Why use our ISA calculator?
An ISA is a tax-efficient way to invest for the long term. Our calculator can help you see what yours could be worth in future. Or work out what you should be investing to reach your future goals.
How our ISA calculator works
To work out your results, our calculator assumes a few things.
Assumptions:
- To get the tax benefit on the investment growth we’ve calculated, you’ll need to stay within your annual ISA allowance.
- Growth rates are examples only (2%, 5% and 8%) - actual growth rates will depend on how your investments perform and could be higher, lower, or negative.
- We haven’t included the effect of inflation, which will reduce the spending power of any money you get back.
- Your results are based on you continuing the same monthly payments for the length of your investment.
Charges:
- We've included charges of 0.70% on your investments as an example, and this includes the Aviva Charge and the fund manager charge.
- For a £10,000 investment that would mean a charge of £70 a year.
- Actual charges may be higher or lower than that amount. They’ll depend on your investments and the providers you choose.
ISA calculator
By trying some numbers you can see what your ISA investments could be worth in future.
Enter a lump sum, regular payment or both. Then just choose the length of your investment in years and the growth rate you’re aiming for.
Plan for your future today
Our flexible ISA lets you withdraw money and pay it back without affecting your £20,000 ISA allowance. And it comes with a range of easy investment options.
Aviva Stocks & Shares ISA
Aviva Stocks & Shares ISA Start your ISA from just £25 a month or a lum sum of £500. Check your investments and make payments easily online, or with the MyAviva app.
Transfer an ISA
Transfer an ISA If you're looking for a new home for your ISAs, there's no charge from us to transfer them to Aviva.
Learn about ISAs
We have a range of simple guides and calculators that can help you understand ISAs and make the most of tax-free investing.
Benefits
What is a stocks and shares ISA?
Understand the tax benefits and rules of investing using a stocks and shares ISA.
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Comparisons
Cash ISA versus stocks and shares ISA
We’ll explain the differences, to help you choose.
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Investments
How much can I invest in a stocks and shares ISA?
Understand the rules on paying into your ISAs.
Inflation calculator
Work out how inflation could affect your returns.
Fees and charges calculator
Understand the fees you could pay with Aviva.
ISA FAQs
What is the annual ISA allowance?
For the 2025/2026 tax year you have a personal ISA allowance of £20,000 which can be split across any stocks & shares, cash or other ISAs that you may have.
For more read our guide to ISA allowances.
Can I have more than one ISA?
Yes. You can have as many ISAs as you want, you just have to make sure any payments stay within your total ISA allowance. Others, like Lifetime ISAs or Junior ISAs have their own rules. We have more information on ISA account rules and limits here.
The next steps for your ISA
If you’re looking to invest in a tax-free way or want a new home for your ISAs, we can help.
Explore an ISA
An Aviva Stocks & Shares ISA has a range of easy investment options, and you can start one from just £25 a month.
Transfer your ISA
If you’re looking for a new home for your ISAs, we won’t charge you to transfer them to us.
Explore investment funds 
Funds are an easy way to start investing. At Aviva we have a wide range to suit your experience and goals.