Franklin to Coulomb Converter

How it is calculated

Enter a charge and choose the direction. The conversion uses one fixed factor between the franklin (Fr, also called the statcoulomb) and the coulomb (C):

1 Fr = 3.335640951982 × 10−10 C

In Franklin → Coulomb mode the tool computes C = Fr × 3.335640951982×10−10. In Coulomb → Franklin mode it computes Fr = C ÷ 3.335640951982×10−10. Results are printed in scientific notation with six decimals in the mantissa, such as 4.803205e-10, using a decimal point in every language. The tool also lists the rate in both directions, where 1 C is about 2.997925×10⁹ Fr. Zero and negative charges are accepted, and the sign is carried through. Values can be typed in scientific form like 1.6e-19.

Common mistakes

• Choosing the wrong direction. Typing a charge in coulombs while the mode is Franklin → Coulomb multiplies by 3.3×10⁻¹⁰ instead of dividing and gives a number about 10¹⁹ times too small.
• Misreading the exponent. The output 4.803205e-10 means 4.803205 × 10⁻¹⁰, a very small number, not 4.8 times ten.
• Typing a number with a decimal comma or with spaces. Use a decimal point and, for very small or large values, the e form such as 1.6e-19.
• Assuming the franklin is a SI-based unit, so that it can be mixed directly into coulomb-based formulas. Gaussian equations such as Coulomb's law have no ε₀, so the same numbers do not drop into SI formulas without converting.
• Confusing the franklin with the faraday or with ampere-hours. The franklin is a very small charge, about 3.3×10⁻¹⁰ C, whereas those units are enormously larger.