How is daily balance interest calculated?

Daily interest is calculated as: (Daily Balance × Annual Interest Rate) / 365. This is summed for each day of the month to get total monthly interest.

Does this tool handle leap years?

Yes, the calculator automatically detects leap years and uses 366 days for leap year calculations and 365 for regular years.

Can I add multiple deposits?

Yes, in Advanced Mode you can add multiple deposits with different dates. Each deposit affects the daily balance from that date forward.

Yes, all calculations happen in your browser. Your data is never sent to any server or stored anywhere.

What rounding rules are used?

We use bank-style rounding (round half up) to match most financial institutions. Interest is rounded to 2 decimal places.

Daily Balance Interest Calculator

Calculate monthly interest earnings on your savings account with daily balance tracking. Understand how deposits throughout the month affect your interest.

Mode

Account Details

Opening Balance ($):

Annual Interest Rate (%):

Month & Year:

Compounding:

Account Details

Opening Balance ($):

Annual Interest Rate (%):

Month & Year:

Compounding:

Deposits During Month

Date	Deposit Amount ($)	Action

Verification (Optional)

Interest Credited by Bank ($):

Enter the actual interest credited by your bank. This will calculate the effective interest rate and compare it with your expected rate.

Use Cases

🏦

Verify Bank Interest

Check if your bank calculated interest correctly for the month

💡

Plan Deposits

Understand how deposits during the month affect your interest earnings

📊

Compare Accounts

Calculate potential earnings for different savings accounts side by side

🎓

Learn Finance

Understand how daily balance interest works with real examples

How to Use

Choose between Simple Mode (basic calculation) or Advanced Mode (with deposits)
Enter your opening balance and annual interest rate
Select the month and year you want to calculate interest for
In Advanced Mode, add deposits with dates to track daily balance changes
Click "Calculate Interest" to see your results and daily breakdown
Optionally enter bank interest to verify and compare calculations

How It Works

Simple Mode: Assumes constant balance throughout the month - calculates interest based on daily rate
Advanced Mode: Tracks daily balance changes from deposits throughout the month
Daily Interest Formula: Daily Interest = (Daily Balance × Annual Rate) ÷ 365
Leap Year Handling: Automatically adjusts for leap years when necessary
Bank Verification: Compare your calculated interest against actual bank credit
Daily Breakdown: View line-by-line report showing each day's balance and interest accrual
Copy Results: Easily copy or export calculations for records

Interest Calculation Tips

Use Simple Mode for quick estimates with steady balances
Switch to Advanced Mode when deposits are made during the month
Enter deposits on the exact date they were made for accuracy
Compare results with your bank statement to verify calculations
Higher rates and earlier deposits earn more interest
Daily breakdown shows which deposits had the most impact

Micro Tools

Daily Balance Interest Calculator

Mode

Account Details

Results

Account Details

Deposits During Month

Verification (Optional)

Calculation Results

Daily Interest Breakdown

Use Cases

Verify Bank Interest

Plan Deposits

Compare Accounts

Learn Finance

How to Use

How It Works