Logarithmic Equation Solver
Solve equations of the standard textbook form log_b(x + c) = d for x by rewriting them in exponential form: x = b^d − c.
Inputs explained
- Right-hand side d — The value the logarithm equals.
- Log base b — The base of the logarithm — 10, e, or 2.
- Constant c added to x — The constant added to x inside the logarithm. Leave 0 for a plain log_b(x) = d equation.
How to use it
- Fill in the fields above — each input has a hint describing exactly what to enter
- Press Calculate to get your result instantly, right on this page
- Copy the result, save the tool to favorites, or share and embed it anywhere
Understanding the result
Example: For log₁₀(x + 2) = 3, x = 10³ − 2 = 998.
Frequently asked questions
Why can't this solver handle every type of logarithmic equation? It's built specifically for the single standard form log_b(x + c) = d, so equations with logs on both sides, different bases combined, or products/quotients inside the log need to be algebraically rearranged into that form first.
Can the solved value of x come out negative? Yes, x itself can be negative, but x + c (the quantity inside the log) must stay positive for the original equation to be valid — the calculator computes x = b^d − c without separately checking this domain restriction.
Is the Logarithmic Equation Solver free to use? Yes — it is completely free, with no sign-up, no download and no usage limits. You can use it as often as you need.
Is my data private? Yes. The calculation runs entirely in your browser — the values you enter are never sent to our servers, stored or shared with anyone.
What information do I need? Just the following: Right-hand side d, Log base b, Constant c added to x. Each field includes a hint explaining exactly what to enter.
Can I use it on my phone? Yes — the tool is fully responsive and works on any device, and the same calculator is available in the EasyWorkCalcs mobile app.
Privacy
Everything you enter into the Logarithmic Equation Solver is processed entirely in your browser. Nothing is uploaded, stored or shared — your data stays on your device.