Exponential Growth and Decay Calculator
Exponential growth is when an amount grows by the same percentage each year, so the increase itself keeps getting bigger. Decay is the same idea with a shrinking amount. This shows where a steady rate ends up.
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- Works offline after your first visit
- Saves on this device
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- Updated
How it works
Each year the amount is multiplied by one plus the rate. Over several years that multiplication is repeated the same number of times, which the power sign stands for.
Enter a negative rate for decay. A rate of minus 10 means the amount loses 10% each year and shrinks over time.
Worked example
Starting at 1,000 and growing 5% a year for 10 years, the amount ends at 1,628.89, a change of 628.89.
Questions
Is a savings account growing like this?
Yes, when interest is added once a year and nothing is taken out. Interest added more often gives a slightly bigger result.
How is this different from a straight-line change?
A straight-line change adds the same amount each year. Here the change is a percentage of the amount, so it gets bigger as the amount grows.
Can the rate be more than 100%?
Yes. A rate of 100% doubles the amount each year, and higher rates grow even faster.
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