Est. 2024 — Open 24/7

The Calculator Store for Everyday Decisions

Walk in, find what you need, get your answer. Free online calculators and utility tools for finance, health, home, and daily life — organized like a well-stocked hardware store.

Browse the Shelves →
Featured

Window Display

Finance

Compound Interest Calculator

"The one tool every regular asks for — see how your savings actually grow over the years."

Try it → Debt

Debt Snowball vs. Avalanche

"Two ways to tackle debt — this shows you which one saves more for your situation."

Try it → Retirement

FIRE Calculator

"How many years until you never have to work again? Plug in the numbers and find out."

Try it → Life

Cost of Living Comparison

"Thinking about relocating? See what your paycheck actually buys in another city."

Try it →
Aisle 1

Daily Essentials

Income

Hourly Wage to Salary

Convert hourly rate to annual, monthly, or weekly pay
Shopping

Discount Price

Quickly figure out the sale price and how much you save
Time

Days Between Dates

Count the exact days, weeks, or months between any two dates
Kitchen

Cup to Gram Converter

Cups to grams, tablespoons to ounces — no more guessing
Dining

Discretionary Income

Money left after essentials — know what you can actually spend
Health

Fat Loss Rate Calculator

Track a realistic and sustainable pace for losing weight
Travel

Food Cost Percentage

Figure out your food cost ratio for any meal or recipe
Fun

Age in Days

How many days have you been alive? Now you'll know
Aisle 2

Specialty Tools

Investment

Cost of Debt Calculator

Calculate the effective rate a company pays on its debt
Corporate

LBO Return Calculator

Model leveraged buyout returns and IRR scenarios
Logistics

Freight Cost Calculator

Estimate shipping costs across carriers and modes
Finance

EVA Calculator

Measure true economic profit after cost of capital
Marketing

AOV Calculator

Calculate average order value across your store
Sustainability

EV Fleet Transition Cost

Model the full cost of switching a fleet to electric
Education

529 College Savings

Project your 529 plan growth vs. future tuition costs
Business

Ghost Kitchen Startup Cost

Estimate the capital needed to launch a delivery-only kitchen
Backroom

Backroom Stock

APR Calculator

FIN
Calculate the true annual percentage rate on a loan

Asset Turnover

FIN
Measure how efficiently a company uses its assets

Balloon Mortgage

FIN
Calculate payments on a balloon mortgage structure

Beta Calculator

FIN
Measure a stock's volatility relative to the market

Break-Even Units

BIZ
How many units do you need to sell to cover costs?

Business Cash Flow

BIZ
Track operating, investing, and financing cash flows

CAC Calculator

MKT
Calculate customer acquisition cost across channels

Closing Cost

FIN
Estimate home purchase closing costs by state

Coupon Campaign ROI

MKT
Measure the return on a coupon discount campaign

Debt-to-Income Ratio

FIN
Calculate your DTI ratio for mortgage qualification

Employee Cost

BIZ
True cost of an employee beyond base salary

Escrow Payment

FIN
Monthly escrow including taxes, insurance, and PMI

Factoring Calculator

FIN
Cost of selling accounts receivable to a factor

FHA Loan Calculator

FIN
Monthly payment and upfront MIP for FHA loans

Franchise Fee

BIZ
Total cost of opening a franchise location

Gross Profit Margin

FIN
Calculate gross margin from revenue and COGS
About

Shopkeeper's Note

Orbitengine started the way most good stores do — we couldn't find what we needed, so we built it ourselves. Every calculator here was made because someone we know had a real question and couldn't find a straight answer online.

We organize things the way a hardware store does: by what you're trying to do, not by abstract categories. Need to figure out a loan? That's Aisle 1. Evaluating an investment? That's Aisle 2. Just need a quick unit conversion? That's up front by the register.

No accounts, no paywalls, no email gates. Walk in, get your answer, get on with your day. We'll be here when you need us again.

🛠

Tools in Stock

300+

🕐

Hours

Open 24/7

🆓

Price

Always Free

FAQ

Customer Questions

They use standard, well-established formulas — the same ones financial advisors and accountants use. We review them regularly and update reference values like tax brackets and average rates when new figures come out. That said, they're built for personal decision-making and planning, not for filing official paperwork. If you're submitting something to the IRS or a court, have a professional double-check the numbers.
Nope. Everything runs right in your browser — nothing gets sent to our servers or saved anywhere. Close the tab and your numbers are gone. We don't require accounts, we don't track what you calculate, and we don't sell data. Think of it like a calculator on a store counter: you use it, you walk away.
Absolutely — we're always looking to stock new shelves. If there's a calculator you wish existed but can't find, let us know through the contact page. Some of our most-used tools started as customer requests. If it's a calculation people actually need, we'll build it.
Every tool is free and open — no sign-up needed, no usage caps, no premium tier. If your team needs calculators, just share the link. Want to embed a specific calculator on your own internal page? Reach out and we can talk about it. We're friendly.
No catch. We keep the lights on through unobtrusive advertising — no pop-ups, no interstitials, no "subscribe to unlock." The calculators are the product, and they stay free because enough people find them useful and come back. That's the whole business model. A good hardware store doesn't charge you to walk down the aisle.