Dose Equivalent Converter

Millisievert vs Microsievert Explained

A millisievert (mSv) is 1,000 times larger than a microsievert (μSv). This page compares the two radiation dose equivalent units, explains when each is used, and includes a bidirectional converter for quick reference.

mSv
×1,000
μSv
1 mSv = 1,000 μSv

How Millisievert and Microsievert Compare

The millisievert (mSv) and microsievert (μSv) both measure dose equivalent — the biological impact of ionizing radiation on human tissue. The only difference is scale: 1 mSv = 1,000 μSv. Millisieverts are used for annual exposure limits and medical procedure doses, while microsieverts are used for real-time dosimeter readings and individual low-dose events.

For context, natural background radiation averages about 2.4 mSv per year (2,400 μSv/yr), a chest X-ray delivers about 0.02 mSv (20 μSv), and the occupational limit for radiation workers is 20 mSv (20,000 μSv) per year. Choosing mSv vs μSv depends on the magnitude of the dose being described.

This page includes a bidirectional converter — enter a value in either field (mSv or μSv) to convert instantly. Below, the conversion chart and FAQ cover the most common radiation dose scenarios.

Millisievert to Microsievert Conversion Formula

μSv = mSv × 1,000

To convert mSv → μSv: multiply by 1,000. To convert μSv → mSv: divide by 1,000. The factor is always 10³ because milli = 10⁻³ and micro = 10⁻⁶.

Example: 1 mSv = 1,000 μSv. 0.02 mSv = 20 μSv. 2,400 μSv = 2.4 mSv.

Millisievert vs Microsievert Reference Chart

Millisieverts Microsieverts Example Real-World Use

The comparison chart below shows common radiation doses in both mSv and μSv side by side, from everyday exposure to medical procedures.

Frequently Asked Questions

What is the difference between mSv and μSv?

Both measure dose equivalent (biological impact of radiation). A millisievert (mSv) is 1,000 times larger than a microsievert (μSv). Millisieverts are used for cumulative and procedural doses; microsieverts for real-time measurements.

When should I use mSv vs μSv?

Use mSv for annual exposure summaries, dose limits, and medical procedure totals. Use μSv for hourly dose rates, single low-dose events (like a dental X-ray), and real-time dosimeter displays.

Is 1 mSv dangerous?

No. 1 mSv is the recommended annual dose limit for the general public above natural background (about 2.4 mSv/yr). The total of ~3.4 mSv/yr carries negligible additional health risk.

How many μSv per hour is safe?

Natural background is about 0.1–0.3 μSv/hr. Dose rates up to a few μSv/hr are within normal ranges. Occupational alerts typically trigger at 10–25 μSv/hr, depending on the country and industry.

What radiation unit do Geiger counters display?

Most consumer Geiger counters display in μSv/hr. Professional instruments can switch between μSv/hr and mSv/hr. Some older models display in counts per minute (CPM) or millirem per hour (mR/hr).