Overdraft Calculator 2026 — UK Bank Charges
Instantly estimate your UK bank overdraft interest, monthly fees, and total charges. Supports arranged & unarranged overdrafts, interest-free buffers, and current EAR rates.
Arranged, Unarranged, or Comparison?
Whether you’re planning a short-term arranged overdraft or worried about unarranged charges, pick the tool below to get an instant, accurate breakdown of your bank fees.
Arranged Overdraft Calculator
Calculate interest and fees for pre-agreed bank overdrafts
Total amount you plan to borrow
Number of days you will be overdrawn
Check your bank app for your exact EAR. Most major UK banks charge between 19.9% and 39.9%.
e.g., first £50 or £100 is interest-free
Most banks charge £0 since 2020 FCA rules
Overdraft Charge Result
Total interest, fees, and repayment breakdown
Enter your overdraft amount and duration, then click Calculate Bank Charges.
Unarranged Overdraft Calculator
Estimate emergency charges for spending beyond your limit
Amount spent beyond your available balance
Days until you can repay the shortfall
Unarranged overdrafts typically carry the maximum allowable EAR.
Fee per declined transaction (if applicable)
How many transactions were declined
Unarranged Charge Result
Penalty interest, refused fees, and total cost
Enter your unarranged overdraft details, then click Calculate Emergency Charges.
Major UK Bank Overdraft Quick Reference
Typical arranged overdraft EAR rates for major UK retail banks. Rates are subject to change and depend on your individual credit assessment. Always verify with your bank’s latest tariff guide.
| Bank | Typical Arranged EAR | Interest-Free Buffer | Notes |
|---|---|---|---|
| Barclays | 19.9% – 39.9% | Up to £100 (select accounts) | Rate depends on creditworthiness |
| HSBC | 19.9% – 39.9% | Up to £100 (select accounts) | Monthly fee abolished in 2020 |
| Lloyds Bank | 19.9% – 39.9% | Up to £100 (select accounts) | Simple interest, charged daily |
| NatWest / RBS | 19.9% – 39.9% | Up to £100 (select accounts) | Rate personalised upon application |
| Santander | 19.9% – 39.9% | Up to £100 (select accounts) | 123 Money account may have different terms |
| Monzo | 19.9% – 39.9% | £0 | Instant decisions via app, no fixed fees |
| Starling Bank | 15.0% – 39.9% | £0 | Lower starting rates for eligible customers |
| Chase UK | 19.9% – 39.9% | £0 | No monthly fees, simple daily interest |
UK Overdraft Calculator FAQ
Everything UK consumers need to know about bank overdraft charges, FCA regulations, and managing short-term borrowing.
UK banks calculate overdraft interest using the Effective Annual Rate (EAR). The daily interest rate is derived by dividing the EAR by 365. This daily rate is then multiplied by your overdrawn balance (minus any interest-free buffer) and the number of days you are in overdraft. Interest is typically charged daily and added to your account monthly.
An arranged overdraft is pre-agreed with your bank up to a specific limit, usually carrying a lower interest rate (e.g., 19.9% to 39.9% EAR). An unarranged overdraft occurs when you spend more than your available balance without prior agreement. Banks may charge higher interest rates, refuse the transaction, or apply additional unpaid item fees, though FCA rules now cap unarranged charges to prevent debt spirals.
Since FCA regulations changed in 2020, most major UK banks have abolished fixed monthly or daily fees for arranged overdrafts. Instead, they charge a single, simple interest rate (EAR) on the amount you use. However, some specialist accounts or unarranged overdrafts may still incur fixed fees or refused payment charges.
An interest-free buffer is a small amount of your overdraft limit (e.g., the first £50 or £100) on which the bank does not charge interest. This is designed to help customers manage minor shortfalls without incurring immediate charges. You must check your specific bank account terms to see if a buffer applies.
Using an arranged overdraft responsibly (staying within your limit and repaying regularly) generally has a neutral or slightly positive effect on your credit score, as it shows you can manage credit. However, consistently maxing out your overdraft or dipping into an unarranged overdraft can negatively impact your credit rating and make future borrowing more difficult.
Contact your bank immediately. Under FCA rules, banks must treat customers in financial difficulty fairly. They may offer a temporary payment holiday, reduce your interest rate, or help you set up a structured repayment plan. You can also seek free, independent advice from organisations like StepChange, National Debtline, or Citizens Advice.