Use the form below to do your conversion.
Solution
Step1
Log216391=Log(6391) ÷ Log(21)
Log(6391)= 3.8055688175486
Log(21)=1.3222192947339
Log216391=3.8055688175486 ÷ 1.3222192947339
Ans=2.8781676630384
Step2
Alternatively, the logarithm can be calculated like this.