Use the form below to do your conversion.
Solution
Step1
Log21991=Log(991) ÷ Log(21)
Log(991)= 2.9960736544853
Log(21)=1.3222192947339
Log21991=2.9960736544853 ÷ 1.3222192947339
Ans=2.2659430749634
Step2
Alternatively, the logarithm can be calculated like this.