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value  : 
log2  : 
loge = ln  : 
log10 = lg  : 
logb1  :   b1 : 
logb2  :   b2 : 

The results are rounded to significant digits.

This is a calculator for logarithms. For a given value the logarithms to the base 2, e, and 10 as well as to an arbitrary base b1 are calculated. You may also type in the logarithm to calculate the value. If you know the value and its logarithm you may calculate the corresponding base b2.

Usage: Type the known number into the corresponding input field. After a mouse click on any free space of the window or on the "calculate"-button the calculation is performed. All results are shown. Move the mouse over a short name or click on it to read the full name.
At the start and after pressing the "reset"-button, the dark input fields show the numbers "16" for the base b1 and "2" for the logarithm to the base b2 that will be calculated. These values may be changed when needed. After a mouse click on any free space of the window or on the "calculate"-button the calculation is performed with the new values.
In the case that "2" is given for the logarithm to the base b2, the value is the square of the base b2, or the base is the square root of the value, respectively. In this way this calculator may be used for root and potential calculations.

Example: What is the natural logarithm of the number 10000 ? Type "10000" into the input field for the value. After a mouse click on any free space of the window or on the "calculate"-button you can read the result (ln(10000) = 9.2103).
As another result you can see that for example the decadic logarithm of this number is "4". When the logarithm to the base b2 is set to "2", you can also read the square root of 10000 (this result is 100).

- Large and small numbers are written exponentially. As example 2.3e5 = 2.3⋅105 = 230000 or 4.5e-5 = 4.5⋅10-5 = 0.000045.
- There is no warranty for the conversion. Cactus2000 is not responsible for damage of any kind caused by wrong results.
- Please send an email if you have suggestions or if you would like to see more conversions to be included.

© Bernd Krüger, 26.11.2007

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Bernd Krüger, 2020