Calorie (IT) to Rydberg Converter

Energy Converter

27 units available

Decimals:

From

To

1.920663e+18

1 cal (IT) = 1.920663e+18 Ry

Formula:

Ry = cal (IT) × 1.920663e+18

With your value: 1 cal (IT) = 1.920663e+18 Ry

How big is that?

Everyday references on a logarithmic scale, all expressed in calorie (it) so you can sanity-check the result.

Heartbeat (1/4.2 your value)0.239 cal (IT)

Your value1.00 cal (IT)

AA battery charge (2.4e+3× your value)2.39e+3 cal (IT)

Slice of bread (6.7e+4× your value)6.69e+4 cal (IT)

Daily food intake (2.0e+6× your value)2.01e+6 cal (IT)

Litre of petrol (8.2e+6× your value)8.17e+6 cal (IT)

Other Calorie (IT) to Rydberg conversions

2 cal (IT) to Ry 3 cal (IT) to Ry 4 cal (IT) to Ry 5 cal (IT) to Ry 6 cal (IT) to Ry 7 cal (IT) to Ry 8 cal (IT) to Ry

Calorie (IT) to Rydberg Conversion Table

Calorie (IT) (cal (IT))	Rydberg (Ry)
0.5	9.603316e+17
1	1.920663e+18
2	3.841326e+18
5	9.603316e+18
10	1.920663e+19
15	2.880995e+19
20	3.841326e+19
25	4.801658e+19
50	9.603316e+19
100	1.920663e+20
250	4.801658e+20
500	9.603316e+20
1000	1.920663e+21

Rydberg to Calorie (IT) Conversion Table

Rydberg (Ry)	Calorie (IT) (cal (IT))
0.5	2.603267e-19
1	5.206535e-19
2	1.041307e-18
5	2.603267e-18
10	5.206535e-18
15	7.809802e-18
20	1.041307e-17
25	1.301634e-17
50	2.603267e-17
100	5.206535e-17
250	1.301634e-16
500	2.603267e-16
1000	5.206535e-16

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Calorie (IT) (cal (IT))

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Rydberg (Ry)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Calorie (IT) to Rydberg

To convert from Calorie (IT) (cal (IT)) to Rydberg (Ry), multiply the value by 1.920663e+18.

Formula: Ry = cal (IT) × 1.920663e+18

Reverse: cal (IT) = Ry × 5.206535e-19

Step-by-Step Example

Start with your value in Calorie (IT). For example: 5 cal (IT)
Multiply by the conversion factor: 5 x 1.920663e+18
The result is: 9.603316e+18 Ry

About Calorie (IT)

The calorie (it) (cal (IT)) is a unit of energy and work. One calorie (it) equals 4.1868 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

About Rydberg

The rydberg (Ry) is a unit of energy and work. One rydberg equals 2.179872 × 10^-18 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many Rydberg are in 1 Calorie (IT)?

There are exactly 1.920663e+18 Rydberg in 1 Calorie (IT). This means the conversion factor from Calorie (IT) to Rydberg is 1.920663e+18.

What is the formula to convert Calorie (IT) to Rydberg?

The formula to convert Calorie (IT) to Rydberg is: Ry = cal (IT) × 1.920663e+18. For example, to convert 10 Calorie (IT) to Rydberg, you would multiply 10 by 1.920663e+18.

What is a Calorie (IT)?