Gear Ratio Calculator

Calculate gear ratio and output speed from input speed and tooth counts.

Formula and method

This calculator uses the values you enter and applies the calculation immediately in your browser. The main output formulas are:

  • Gear ratio: drivenTeeth/drivingTeeth
  • Output speed: inputRpm*(drivingTeeth/drivenTeeth)

Some formulas are undefined for certain input combinations, such as division by zero, equal x-values in a slope calculation, or logarithms of non-positive numbers. In those cases the live tool reports that the result is undefined instead of displaying Infinity or NaN.

Examples

  • Example: with Driving gear teeth = 20, Driven gear teeth = 60, Input speed = 1000 rpm, this calculator returns Gear ratio = 3, Output speed = 333.3 rpm.
  • Share this page with a clean URL: https://specwhale.com/tools/gear-ratio-calculator/
  • Try related education & math tools when your next step needs another conversion or calculation.

Embed this tool

Paste this snippet into your own site or blog post to embed a live, working copy of this tool. It links back to the full page on SpecWhale.

Frequently asked questions

Is Gear Ratio Calculator free to use?

Yes. Gear Ratio Calculator is completely free, has no usage limit, and does not require an account, email, or API key.

Does Gear Ratio Calculator store or upload my data?

No. Gear Ratio Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.

How accurate is Gear Ratio Calculator?

Gear Ratio Calculator uses a standard formula (see the Method section above for the exact expression). For high-stakes financial, medical, or legal decisions, confirm the result with a professional or an authoritative source before relying on it.

Can I embed Gear Ratio Calculator on my own website?

Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Gear Ratio Calculator to your own blog post or page.

SEO and sharing notes

This page has a single clean canonical URL, descriptive metadata, breadcrumb structured data, and internal links to related tools. Supported calculators and converters can also copy a prefilled share link without changing the canonical index URL.