UK savings tool
ISA Savings Calculator UK
Use this ISA savings calculator to estimate how your savings could grow over time, compare your planned contributions with the annual ISA allowance, and see how small changes may affect the long-term result.
About this tool
This calculator is designed for general ISA savings planning. It uses the standard annual ISA allowance of £20,000 as a reference point and gives a simplified long-term growth estimate.
Projected ISA value
£98,554
Estimated end value based on the figures entered.
Growth from interest
£21,554
The estimated value added by growth rather than deposits.
ISA summary
Within ISA allowance
Savings score: 90/100
Based on the figures entered, your annual ISA contribution plan appears to sit within the standard annual ISA allowance.
Annual contribution plan
£7,200
Remaining ISA allowance
£12,800
What changes may make the biggest difference?
Current setup
£98,554
If you added £50/month
£106,114
If growth increased by 1%
£104,360
Standard ISA allowance reference
This page uses the standard annual ISA allowance of £20,000 as a planning reference for the current 2026/27 tax year.
How ISA savings growth works
An ISA lets you save or invest within an annual allowance. For the 2026/27 tax year, the annual ISA allowance is £20,000. This calculator compares your planned monthly and annual contributions with that allowance. [oai_citation:0‡GOV.UK](https://www.gov.uk/lifetime-isa?utm_source=chatgpt.com)
The growth estimate uses a simplified compound growth calculation. It assumes regular contributions and a constant annual growth rate, so the final result should be treated as an illustration rather than a guaranteed outcome.
Cash ISA rates and investment returns can change. Investment values can also go down as well as up, so this page is for general planning only and does not provide personal financial advice.
Allowance
The calculator compares your planned annual contributions with the standard ISA allowance.
Contributions
Regular monthly contributions and one-off annual deposits both affect the projection.
Growth
The growth rate is only an assumption and may not reflect real future returns.
How to use this estimate
This page is useful for planning longer-term savings inside an ISA and seeing how a mix of regular monthly contributions and annual deposits may build over time.
The most useful figures to watch are the projected end value, the amount created by growth, and whether the annual contribution plan stays within the ISA allowance.
This calculator gives estimates only and does not provide personal financial advice.
ISA savings calculator FAQs
What is the ISA allowance?
This calculator uses the standard annual ISA allowance of £20,000 for the 2026/27 tax year as a planning reference.
Do I need a large amount to get started?
No. Smaller, consistent contributions may still build over time, especially across longer periods.
Why does time matter so much?
Because compound growth tends to become more visible the longer money is left to build.
Is this calculator financial advice?
No. It provides a general estimate only and should not be treated as personal financial advice.
Next step
Keep building your savings plan
A useful next step may be comparing this with a broader compound growth plan or checking what your monthly budget may realistically support.
Related ISA and savings pages
Compound Interest Calculator
Compare ISA growth with a broader compound growth view.
Monthly Budget Planner
Check how much room your budget has for ISA contributions.
Healthy Savings Rate UK
See how your ISA plan fits into a healthy overall savings rate.
Take-Home Pay Calculator UK
Use your monthly income to judge realistic ISA contributions.
Important
This tool provides general estimates and educational guidance only. It does not account for your full personal circumstances and should not be treated as financial advice or a personal recommendation.