Learning · official-source review · reviewed 2026-10-10
A dose written in milligrams and a spec written in grams are the same number in different clothes.
Convert a value between two SI prefixes and show the base-unit value and the factor between the units.
Students, lab assistants, cooks, and anyone moving a number between SI prefixes.
Use the source document or official route that applies to your situation. This guide does not contact another person or verify external information.
Write the number exactly as the source shows it. Keep the unit beside it.
Read the factor for the prefix you have, such as 0.001 for milli, from the SI prefix table.
Read the factor for the prefix you want. For a plain base unit the factor is 1.
Multiply the value by the first factor. This step removes the old prefix.
Divide the base value by the second factor. Write the new unit beside the answer.
You have 2,500 milligrams and want grams. The base value is 2.5, the result is 2.5 grams, and the factor is 0.001.
Use your own source and details. The example is not a record about a real person or organization.
National Institute of Standards and Technology · reviewed 2026-10-10
What this source supports: NIST SP 811 documents rounding and significant-figure conventions for reported measurements.
Source limit: Individual journals and courses may specify their own reporting conventions. Follow the rule your work requires.
These sources support the statements above. They do not show that every person needs this guide. They do not show a specific result.
This guide multiplies and divides by the factors you enter. It does not look up the prefix table or verify your units.
Individual journals and courses may specify their own reporting conventions. Follow the rule your work requires.
Use current instructions from the responsible organization. This guide is a planning aid, not an official decision or a substitute for qualified advice.
Convert a value between two SI prefixes and show the base-unit value and the factor between the units.
This App multiplies and divides by the factors you enter. It does not look up the prefix table, check that your units match, or judge a measurement.
You enter every number yourself. The sources support the method and the limits. They do not produce a result for your specific case. Keep the original documents next to the sheet you build.
The App computes the worked example with your own numbers, in your browser.
APP 1
Convert a value between two SI prefixes and show the base-unit value and the factor between the units.
Free · no account · no upload
Open SI Prefix Conversion CheckThe App runs in this browser. It does not send or save entries. Copy, download, or print only when you choose.
This guide uses short, direct instructions as an ASD-STE100-style writing target. It is not a formal certification.
Companion App: SI Prefix Conversion Check. It runs in this browser and does not upload your entries.
This guide is edited for clarity and checked against the sources it links. It is not a substitute for official instructions or qualified advice. A linked source does not show that every person needs this guide.