Unit & Number Conversion Tools
Switch between units and formats quickly and without mistakes.
Altitude to Pressure Calculator
Convert altitude to air pressure and pressure to altitude. Shows inHg, hPa and psi, plus a pressure chart from 0 to 30,000 ft.
Depth of Field & Star Exposure Calculator
Find the in-focus range, hyperfocal distance, and the longest star-sharp exposure from sensor, focal length, and f-number.
Online Decibel Meter
Measure sound levels with your mic and see max, average, and everyday sound comparisons.
Knitting Gauge Calculator
Convert pattern stitch and row counts to your gauge, find cast-on numbers for a custom size, and estimate skeins.
Add or Remove Commas in Numbers
Add or remove thousands separators in bulk, with Indian and European styles, K/M/B short form, and amounts in words.
Altitude to Pressure Calculator
Convert altitude to air pressure and pressure to altitude. Shows inHg, hPa and psi, plus a pressure chart from 0 to 30,000 ft.
Depth of Field & Star Exposure Calculator
Find the in-focus range, hyperfocal distance, and the longest star-sharp exposure from sensor, focal length, and f-number.
Online Decibel Meter
Measure sound levels with your mic and see max, average, and everyday sound comparisons.
Knitting Gauge Calculator
Convert pattern stitch and row counts to your gauge, find cast-on numbers for a custom size, and estimate skeins.
Add or Remove Commas in Numbers
Add or remove thousands separators in bulk, with Indian and European styles, K/M/B short form, and amounts in words.
Category Overview
What Unit & Number Conversion tools can do for you
5 tools listed
The unit and number conversion tools are for whenever you need a value in a different unit or format. Convert length, weight and temperature, calculate percentages, convert between binary, octal, decimal and hexadecimal, work with Roman numerals and compute golden and silver ratios.
For everyday quantities, convert area, volume, length and weight into comparisons with familiar objects, look up and convert paper sizes (mm, cm, inch and px), compare clothing and shoe sizes between countries and convert currencies using a rate you enter yourself. File size units (KB, MB, GB and KiB, MiB, GiB) and download time estimates are also covered.
For location and measurement, convert latitude and longitude between decimal and degrees-minutes-seconds, calculate distance and bearing between two points, convert between UTM and MGRS and work with Plus Codes and geohashes. There are also photography exposure helpers, shipping load calculators, on-screen rulers and protractors and a large-digit calculator.
Handy when you need to
- ✓ Convert units for a document, quote or recipe
- ✓ Compare paper or image sizes in mm, px and inches
- ✓ Convert coordinates between formats
- ✓ Estimate file size and download time
Pro tip
Conversions specific to a field live in their own categories, such as home and building, cooking and finance. Exchange rates change daily, so check a current rate with your bank.
Unit & Number Conversion: frequently asked questions
- Q. Are exchange rates fetched automatically?
- A. No. The currency converter uses a rate you enter yourself, so you control which rate is applied.
- Q. What is the difference between KB and KiB?
- A. KB usually means 1,000 bytes and KiB means 1,024 bytes. The file size converter shows both families side by side.