Cash ISA Calculator
Estimate how your Cash ISA savings could grow over time using compound interest. Enter your starting deposit, expected interest rate and optional monthly contributions to see how your tax-free savings may grow.
Tip! Cash ISA contributions count toward the £20,000 annual ISA allowance across all ISA accounts.
| Initial Deposit (£) | |
|---|---|
| Interest Rate (%) | |
| Years | |
| Monthly Contribution (£) | |
| Inflation Rate (%) |
How to Use the Cash ISA Calculator
Step-by-Step Instructions
- Enter your starting Cash ISA deposit.
- Add the interest rate offered by your ISA provider.
- Enter how many years you plan to keep the savings invested.
- Optionally add monthly contributions.
- Enter an inflation rate to see real purchasing power.
- Click "Calculate" to estimate future ISA savings.
Why Use a Cash ISA Calculator?
Cash ISAs allow UK savers to earn interest without paying tax on the returns. Forecasting your ISA growth helps you plan savings goals and understand the effect of compound interest over time.
Key Benefits
- Estimate tax-free savings growth over time.
- See the impact of monthly saving habits.
- Compare interest rate scenarios.
- Adjust for inflation to understand real purchasing power.
Important Cash ISA Rules
- The UK ISA allowance is £20,000 per tax year.
- This allowance is shared across all ISA types.
- Cash ISA interest is generally tax-free.
- Providers may offer fixed or variable rates.
- Some accounts may include withdrawal restrictions.
A Cash ISA protects capital unlike investment ISAs, but interest rates may be lower than long-term investment returns.
Understanding Inflation and Savings
Inflation reduces the purchasing power of money over time. Even if your savings grow in nominal terms, the real value may increase more slowly once inflation is considered.
Tips for ISA Savers
- Maximise your ISA allowance where possible.
- Compare interest rates across ISA providers.
- Consider fixed vs variable interest accounts.
- Review inflation assumptions for long-term projections.
Related Guides
- Cash ISA vs Savings Account - Compare tax-free Cash ISAs with traditional savings accounts and interest rates.
- Cash ISA vs Stocks & Shares ISA - Understand when saving or investing through an ISA may be more appropriate.
- UK ISA Allowance & Rules Explained - Learn how ISA contribution limits work and how to use the tax-free wrapper effectively.
Frequently Asked Questions
What is a Cash ISA calculator?
It estimates how your tax-free ISA savings could grow using compound interest and optional monthly contributions.
What is the ISA allowance?
The UK ISA allowance is £20,000 per tax year across all ISA types combined.
Is Cash ISA interest tax-free?
Yes, interest earned inside a Cash ISA is generally tax-free.
Should I adjust for inflation?
Inflation adjustment shows the real purchasing power of your savings rather than just nominal growth.