About Calculator Wizard

Hi, I'm Devon — welcome to Calculator Wizard.

I'll say this upfront: I'm not a math teacher, and I'm not a finance professional. I decided to build this site based on my own needs and the things I found myself researching over and over.

After noticing how many times I'd Googled my way onto someone else's calculator site, I had a simple thought: why not just build my own? My ambition grew from there — the site expanded well beyond my original needs as I started learning to code with the help of AI. Many of the scripts here are AI-generated, but the process of learning HTML along the way has been genuinely exciting, and challenging in the best way.

Why "Wizard"?

Not because I'm an expert. It's because I want using this site to feel a little like magic — type in your numbers, get a clear answer, and actually understand the "why" behind it, not just a black-box result.

What I Actually Care About

Every formula on this site is checked and verified, not guessed at
Every calculator shows its work — not just a number, but the formula and a real worked example
Everything is free to use, with no paywall and no clutter
Nothing asks you to sign up before it will give you an answer

The Debt Payoff Planner

The Debt Payoff Planner is the biggest thing I've built here, and the piece I'm proudest of. It takes everything you owe, runs the real month-by-month math, and shows you the actual date you'll be debt-free — then compares five different payoff strategies side by side so you can see what each one really costs you.

It's free, it's available in English and Spanish, and it never connects to your bank.

About the Optional Account

Most of this site needs no account at all — you type numbers in, you get an answer, that's the whole transaction. The Debt Payoff Planner is the one exception, and only because paying off debt isn't a one-afternoon task.

Creating a free account there lets you do two things you can't do otherwise:

Pick up where you left off. Build your plan on your laptop, check it on your phone at the kitchen table. Your numbers follow you.
Track real progress over time. Log payments as you make them, watch balances fall, and see your payoff date move closer as you go. That's the part that actually keeps people going.

The account is entirely optional. Skip it and the planner works exactly the same — your numbers just stay in your own browser instead of syncing between devices. There's no paid tier, nothing is sold to advertisers, and it never asks for a bank login. See the privacy policy for exactly what gets stored.

What Else Is Here

A growing collection of free tools, including:

Debt Payoff Planner (snowball, avalanche, and three more strategies compared)
Percentage Calculator (percent of, discount, percent change, and more)
Credit Card Payoff Calculator
Mortgage Payment Calculator
Auto Loan Calculator
Investment Growth Calculator
Markup Calculator
Grade Percentage Calculator
Sales Tax Calculator
Traditional Basic & Scientific Calculators

Alongside the calculators, the Guides section covers how percentages and interest actually work in real situations — pay raises, tipping, GPA, compound interest, APR — with worked examples rather than just formulas.

Still Growing

I look forward to growing this site further, and hopefully helping people build real math confidence the same way similar sites have helped me over the years. If there's a calculator you wish existed, or something that looks wrong, reach out — I read every message.

Cheers!
— Devon