What does Doubling Time do that other Finance pages on this site do not?

years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0. Short version: Rule-of-70 style doubling years, months, days.

Does Doubling Time upload my file or text to Tool-You servers?

No. Doubling Time runs in this browser tab. Files stay on the device. Limit note: Annual % > 0. Continuous compounding approximation.

Should I use Rule of 72 instead of Doubling Time?

Use Doubling Time when you need Rule-of-70 style doubling years, months, days. Use Rule of 72 when you need Years to double at a rate, or rate for a target years. They share a category (Finance) but not the same job.

What are the limits of Doubling Time?

Annual % > 0. Continuous compounding approximation. Also: years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.

Doubling Time

Rule-of-70 style doubling years, months, days.

years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.

What Doubling Time does

years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.

Practical limit for Doubling Time: Annual % > 0. Continuous compounding approximation. That is why output can differ from heavy desktop Finance software. Read the tool-specific note again: years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.

How to use Doubling Time

Confirm you need Doubling Time, not Rule of 72 (Years to double at a rate, or rate for a target years.). Address: /finance/doubling-time.
Enter the numbers or dates Doubling Time uses. Rule-of-70 style doubling years, months, days.
Read the result as Doubling Time defines it — not as Compound Interest Calculator (Project compound growth with optional contributions.). years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.
Doubling Time is an estimate in the browser, not professional advice. Annual % > 0. Continuous compounding approximation.
Need a different formula? Try Compound Interest Calculator (Project compound growth with optional contributions.) instead of stretching Doubling Time.

When not to use Doubling Time

Skip Doubling Time when a neighbor tool matches better — start with Rule of 72 or Compound Interest Calculator — or when the description already warns the job will fail. In the tool’s own words: years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.

Questions about Doubling Time

What does Doubling Time do that other Finance pages on this site do not?: years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0. Short version: Rule-of-70 style doubling years, months, days.
Does Doubling Time upload my file or text to Tool-You servers?: No. Doubling Time runs in this browser tab. Files stay on the device. Limit note: Annual % > 0. Continuous compounding approximation.
Should I use Rule of 72 instead of Doubling Time?: Use Doubling Time when you need Rule-of-70 style doubling years, months, days. Use Rule of 72 when you need Years to double at a rate, or rate for a target years. They share a category (Finance) but not the same job.
What are the limits of Doubling Time?: Annual % > 0. Continuous compounding approximation. Also: years = ln(2)/ln(1+r/100); also months and days (365.25). Rate must be > 0.