Logarithm table (log and ln, 1 to 100)

Updated

log₁₀ 2 = 0.3010, ln 2 = 0.6931 and ln 10 = 2.3026. The log of any number from 1 to 100 lies between 0 and 2.

01.152.33.454.61125.850.575.3100
  • log₁₀ n
  • ln n
Logarithm table (log and ln, 1 to 100)
nlog₁₀ nln nlog₂ n
10.00000.00000.0000
20.30100.69311.0000
30.47711.09861.5850
40.60211.38632.0000
50.69901.60942.3219
60.77821.79182.5850
70.84511.94592.8074
80.90312.07943.0000
90.95422.19723.1699
101.00002.30263.3219
111.04142.39793.4594
121.07922.48493.5850
131.11392.56493.7004
141.14612.63913.8074
151.17612.70813.9069
161.20412.77264.0000
171.23042.83324.0875
181.25532.89044.1699
191.27882.94444.2479
201.30102.99574.3219
211.32223.04454.3923
221.34243.09104.4594
231.36173.13554.5236
241.38023.17814.5850
251.39793.21894.6439
261.41503.25814.7004
271.43143.29584.7549
281.44723.33224.8074
291.46243.36734.8580
301.47713.40124.9069
311.49143.43404.9542
321.50513.46575.0000
331.51853.49655.0444
341.53153.52645.0875
351.54413.55535.1293
361.55633.58355.1699
371.56823.61095.2095
381.57983.63765.2479
391.59113.66365.2854
401.60213.68895.3219
411.61283.71365.3576
421.62323.73775.3923
431.63353.76125.4263
441.64353.78425.4594
451.65323.80675.4919
461.66283.82865.5236
471.67213.85015.5546
481.68123.87125.5850
491.69023.89185.6147
501.69903.91205.6439
511.70763.93185.6724
521.71603.95125.7004
531.72433.97035.7279
541.73243.98905.7549
551.74044.00735.7814
561.74824.02545.8074
571.75594.04315.8329
581.76344.06045.8580
591.77094.07755.8826
601.77824.09435.9069
611.78534.11095.9307
621.79244.12715.9542
631.79934.14315.9773
641.80624.15896.0000
651.81294.17446.0224
661.81954.18976.0444
671.82614.20476.0661
681.83254.21956.0875
691.83884.23416.1085
701.84514.24856.1293
711.85134.26276.1497
721.85734.27676.1699
731.86334.29056.1898
741.86924.30416.2095
751.87514.31756.2288
761.88084.33076.2479
771.88654.34386.2668
781.89214.35676.2854
791.89764.36946.3038
801.90314.38206.3219
811.90854.39446.3399
821.91384.40676.3576
831.91914.41886.3750
841.92434.43086.3923
851.92944.44276.4094
861.93454.45436.4263
871.93954.46596.4429
881.94454.47736.4594
891.94944.48866.4757
901.95424.49986.4919
911.95904.51096.5078
921.96384.52186.5236
931.96854.53266.5392
941.97314.54336.5546
951.97774.55396.5699
961.98234.56436.5850
971.98684.57476.5999
981.99124.58506.6147
991.99564.59516.6294
1002.00004.60526.6439
Need a value that is not in the table? Open the calculator : Logarithm Change Of Base →

How it is computed

log₁₀ n is the power of 10 that gives n, ln n the power of e (≈ 2.71828) and log₂ n the power of 2. The three differ only by a constant factor: ln n = log₁₀ n × ln 10. Values are rounded to four decimals.

FAQ

How do I get the log of a number above 100?+

Factor out powers of ten: log₁₀ 2,500 = log₁₀ 25 + 2. This is how printed log tables were used before calculators.

What is the log of 0 or a negative number?+

It is undefined: no power of a positive base gives 0 or a negative result. As n approaches 0, the log falls toward minus infinity.