Break-Even Time Calculator Formula

Understand the math behind the break-even time calculator. Each variable explained with a worked example.

Use the Break-Even Time Calculator

Formulas Used

Months to Break Even

months_to_break_even = ceil(upfront_cost / monthly_savings)

Years to Break Even

years_to_break_even = upfront_cost / monthly_savings / 12

Net Savings After 5 Years

five_year_net = monthly_savings * 60 - upfront_cost

Variables

VariableDescriptionDefault
upfront_costUpfront Cost(USD)1200
monthly_savingsMonthly Savings(USD/mo)80

How It Works

How to Calculate Break-Even Time

Divide the upfront cost by the monthly savings to find when the investment pays for itself.

Formula

Break-Even Months = Upfront Cost / Monthly Savings

After break-even, every month of continued savings is pure profit.

Worked Example

You spend $1,200 on energy-efficient appliances that save $80/month.

upfront_cost = 1200monthly_savings = 80
  1. 01Break-even months = ceil($1,200 / $80) = 15 months
  2. 02Break-even years = 15 / 12 = 1.3 years
  3. 03Net savings after 5 years = $80 x 60 - $1,200 = $3,600

Ready to run the numbers?

Open Break-Even Time Calculator