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Earth Science Calculators

Geologic Time Calculator

Place a date in the geologic time scale, and scale Earth’s history onto a single calendar year.

Enter values

Results update as you type.

Result

Geological period

Paleogene

Years ago
66,000,000
Fraction of Earth’s history
1.435% ago
On a one-year calendar of Earth
26 December
Human history (200,000 yrs) on that scale
31 December, 23:37

About the Geologic Time Calculator

Place a date in the geologic time scale, and scale Earth’s history onto a single calendar year.

Also known as: geological time scale, millions of years ago, earth history calculator, mya calculator.

How to use this calculator

  1. Enter millions of years ago.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

Earth is 4,600 million years old — scale any date against that

Worked example

Using the values pre-filled in the calculator above:

  • Millions of years ago = 66

the calculator returns:

  • Geological period: Paleogene
  • Years ago: 66,000,000
  • Fraction of Earth’s history: 1.435% ago
  • On a one-year calendar of Earth: 26 December