How to calculate bill increase?

To calculate a bill increase percentage, first subtract the old bill amount from the new bill amount. Then, divide this difference by the old bill amount and multiply by 100. This reveals exactly how much more you are paying relative to your previous rate.

Formula

Increase % = ((New Bill − Old Bill) ÷ Old Bill) × 100

Worked Example

Your internet bill went from $50 to $65.

1. Difference: $65 − $50 = $15
2. Ratio: $15 ÷ $50 = 0.30
3. Percentage: 0.30 × 100 = 30%

Result: Your bill increased by 30%.