The Calculator App
Savings
Calculator App
Free UK savings calculator app. Model savings growth with any AER, regular contributions, and one-off deposits. No download. Works on iPhone and Android.
Savings tools in the app
Savings Calculator
Project savings growth with AER and regular contributions
ISA Calculator
Model Cash ISA and Stocks & Shares ISA growth tax-free
Compound Interest Calculator
Full investment growth model with weekly/monthly contributions
Savings Goal Calculator
Calculate how long to reach a savings target
How Much to Save
Work out monthly savings needed to hit a goal by a deadline
Retirement Calculator
Model pension pot growth to your target retirement age
UK savings account rates at a glance (2026)
| Account | Typical AER | Interest Taxed? |
|---|---|---|
| Easy Access | 3.5–5.0% | Yes (PSA applies) |
| Fixed Rate Bond (1yr) | 4.0–5.2% | Yes (PSA applies) |
| Cash ISA | 3.5–5.0% | No — fully sheltered |
| Lifetime ISA | up to 6.25% incl. bonus | No |
| Premium Bonds | ~4.4% prize equivalent | No |
Worked example
£5,000 starting, £300/month, 4.5% AER, 10 years:
Frequently asked questions
Is there a free savings calculator app in the UK?
Yes. The Calculator App is a free savings calculator that works on iPhone and Android with no download. Enter your starting amount, monthly contributions, AER, and time period — it instantly shows your final balance and total interest earned.
What is the best savings calculator app?
The best savings calculator app lets you model different account types (Cash ISA, fixed-rate bond, easy access), add regular contributions, and compare AER rates. The Calculator App does this for free with no sign-up.
How do I calculate my savings with interest?
Use the compound interest formula: FV = P(1 + r/n)^(nt) + PMT × [((1+r/n)^(nt) − 1) / (r/n)]. Or just open The Calculator App, enter your numbers, and get the answer instantly.
What is AER and why does it matter?
AER (Annual Equivalent Rate) is the true annual return on savings, accounting for compounding. It's the number you should compare between accounts — a 4.5% AER monthly account beats a 4.5% AER annual account in practice because interest compounds more often.
Does the savings app include Cash ISA calculations?
Yes. The savings calculator works for any account type. For Cash ISAs specifically, there is also a dedicated ISA Calculator in the app that models annual allowance top-ups and tax-free growth over 10–30 years.
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