How do you convert becquerels to curies?

To convert becquerels (Bq) to curies (Ci), multiply the measurement in becquerels by 2.702703e-11 (curies = becquerels × 2.702703e-11).

What is 5 becquerels in curies?

5 becquerels (5 Bq) is equal to 1.351351e-10 curies (1.351351e-10 Ci).

Which is larger, 1 becquerel (Bq) or 1 curie (Ci)?

One curie (Ci) is larger than one becquerel (Bq). Specifically, 1 Ci equals 3.700000e+10 Bq, while 1 Bq is 2.702703e-11 Ci.

How do I convert back from curies (Ci) to becquerels (Bq)?

To reverse the calculation from Ci to Bq, multiply your curie value by the inverse factor 3.700000e+10 (or divide by 2.702703e-11). You can also click the Swap button in the tool above to flip directions in one click.

How many decimal places should I round Bq to Ci results to?

For everyday comparisons and quick estimates, rounding to 2 decimal places is usually sufficient (for example, 5 Bq ≈ 0.00 Ci). For engineering, laboratory, or machining specifications, select 4 or 6 decimals—or Scientific (10ⁿ) mode—in the calculator toolbar above.

Becquerels to Curies Converter

Enter the radioactive activity in becquerels below to convert it to curies.

Curies to Becquerels (Ci → Bq)

Convert Becquerels to Curies

Enter a value in becquerels (Bq) to convert to curies (Ci).

Value (Bq)

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Result

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1.351351e-10curies

5 Bq = 1.351351e-10 Ci

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Suggested Conversions

Reference:NIST OWM (SI Units — Length)

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Becquerel to Curie Conversion Table

Table showing various becquerel measurements converted to curies. Click any preset value or arrow to load it into the converter.

Becquerels (Bq)	Curies (Ci)
1 Bq	2.702703e-11 Ci
10 Bq	2.702703e-10 Ci
100 Bq	2.702703e-9 Ci
1,000 Bq	0.000000027 Ci
10,000 Bq	0.00000027 Ci
100,000 Bq	0.000002703 Ci
1,000,000 Bq	0.000027027 Ci
5,000,000 Bq	0.000135135 Ci
10,000,000 Bq	0.00027027 Ci
25,400,000 Bq	0.000686486 Ci

How to Convert Becquerels to Curies

To convert becquerels to curies, multiply the radioactive activity by the following conversion ratio: 2.702703e-11 curies/becquerel.

Since one becquerel is equal to 2.702703e-11 curies, you can use this simple formula to convert:

curies = becquerels × 2.702703e-11

The radioactive activity in curies is equal to the radioactive activity in becquerels multiplied by 2.702703e-11.

For example, here's how to convert 5 becquerels to curies using the formula above.

curies = (5 Bq × 2.702703e-11) = 1.351351e-10 Ci

How Many Curies Are in a Becquerel?

There are 2.702703e-11 curies in a becquerel, which is why we use this value in the formula above.

1 Bq = 2.702703e-11 Ci|1 Ci = 37,000,000,000 Bq

Our becquerel to curie calculator automatically converts your radioactive activity measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

Becquerels and curies are both units used to measure radioactive activity. Keep reading to learn more about each unit.

What Is a Becquerel?

SI derived unit of radioactivity equal to 1 nuclear decay per second. It serves as a primary reference unit for measuring radioactive activity across scientific and practical applications. [1]

The becquerel is classified as an International System of Units (SI) unit of radioactive activity. Becquerels can be abbreviated as Bq; for example, 1 becquerel can be written as 1 Bq.

As the primary coherent reference unit for radioactive activity in this category, all other radioactive activity units are mathematically anchored to the becquerel (Bq).

In practice, becquerels (Bq) are widely used across standard radioactive activity applications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.

Learn more about becquerels in our Radiation-Activity Converter.

What Is a Curie?

A curie is a unit of radioactive activity equal to 37,000,000,000 becquerels (Bq), the base unit for radioactive activity. Traditional radioactivity unit equal to 3.7×10¹⁰ Becquerels (37 GBq). [2]

The curie is classified as a standard unit of radioactive activity. Curies can be abbreviated as Ci; for example, 1 curie can be written as 1 Ci.

When working with curies (Ci) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, curies (Ci) are widely used across large-scale industrial, bulk, and macro-level radioactive activity specifications within international standard workflows, engineering documentation, and technical data sheets.

Learn more about curies in our Radiation-Activity Converter.

When converting radioactive activity between becquerels (Bq) and curies (Ci), keep full floating-point precision (1 Bq = 2.702703e-11 Ci; 1 Ci = 37,000,000,000 Bq) during intermediate calculations and round only the final curie figure to match your instrument tolerance.

More Becquerel & Curie Conversions

Need to calculate in the opposite direction? Use our curies to becquerels calculator to switch your starting unit immediately. You can also explore related tools such as converting curies to becquerels, converting becquerels to kilobecquerels, or converting becquerels to megabecquerels.

Convert from Becquerels

Convert to Curies

Frequently Asked Questions

There are 2.702703e-11 curies (Ci) in 1 becquerel (Bq). Conversely, 1 curie (Ci) is equal to 3.700000e+10 becquerels (Bq).

Radiation-Activity Converter

Quick Info

Direct Factor: 1 becquerel (Bq) equals 2.702703e-11 curies (Ci).
Inverse Factor: 1 curie (Ci) equals 3.700000e+10 becquerels (Bq).
Formula: curies = becquerels × 2.702703e-11.
Verified Precision: Anchored to official NIST SP 811 and ISO/IEC 80000 standards.

Units Comparison

Becquerel (Bq)

SI derived unit of radioactivity equal to 1 nuclear decay per second.

Curie (Ci)

Traditional radioactivity unit equal to 3.7×10¹⁰ Becquerels (37 GBq).

Kilobecquerel (kBq)

Equal to 1,000 Becquerels.

References

[1]NIST OWM · SI Units — Length
Source
[2]BIPM · SI Base Unit: Metre (m)
Source
[3]NIST HB 133 · NIST Handbook 133 (2019 Ed.)
Source

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References

NIST · BIPM · ISO

[1]
NIST OWM (SI Units — Length)·Radiation-Activity Metrology Standard — Becquerels (Bq) to Curies (Ci)
NIST OWM Standard
[2]
BIPM (SI Base Unit: Metre (m))·Unit Specifications: Becquerel (Bq) & Curie (Ci)
BIPM Specification
[3]
NIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (Bq to Ci)
NIST HB 133 Reference

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