Antilogarithm Calculator

This antilogarithm calculator reverses a logarithm. If a logarithm answers the question, to what power do I raise the base to get this number, the antilogarithm goes the other way: it raises the base to the given power. Enter the logarithm value and the base and the calculator returns the antilog, plus the natural antilog using the base e for reference. Antilogs were essential in the days of log tables and slide rules, and they remain a clear way to undo a log, for example converting a pH or a decibel figure back to a concentration or a ratio. The formula, a worked example and the assumptions are set out below.

Logarithm value (L)

Base (b)

Natural antilog (e^L)

Base

The formula

The antilogarithm of L in base b is b raised to the power L, that is antilog_b(L) = b^L. With base 10 it is 10^L, and the natural antilog is e^L. It is the inverse of the logarithm.

Worked example

The base 10 antilog of 2 is 10^2 = 100, because log base 10 of 100 is 2. The natural antilog of 2 is e^2, about 7.389056. Enter 2 and 10 to confirm.

Frequently asked questions

What is an antilogarithm?

The inverse of a logarithm. The antilog of L in base b is b to the power L, undoing the log.

What is the antilog of 2 in base 10?

100, since 10 squared is 100.

What base should I use?

Use 10 for common logs, e for natural logs, or any positive base other than 1 to match your log.

Who this calculator is for

This calculator is for students and anyone needing a quick, reliable result.

What this calculator assumes

You enter valid numbers.
The standard formula is applied.
Results are rounded for display.

Formula and sources

Related calculators

Scientific Calculator: general scientific maths.
Percentage Calculator: percentages and changes.
Ratio Calculator: simplify and scale ratios.

If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.

Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.

All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.

Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.

Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.

Calculate.co.nz is hosted in Auckland via SiteHost new Zealand.

All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.

About & trust: Why Calculate is NZ's most comprehensive · By the Numbers · How we compare · Editorial standards · How we keep data current · NZ finance glossary · Research & data · Financial literacy NZ · About · Privacy policy · Terms of use

Reviewed and maintained. Last reviewed 2026-06-21 and checked on a twice-monthly cycle against IRD, RBNZ and Stats NZ. How we keep data current.