Free Business Calculators
The gap between what you charge and what you keep is where small businesses quietly lose money. A price that looks profitable on paper shrinks after the payment processor takes its cut, the platform takes its commission, and the cost side turns out higher than the back-of-the-envelope math assumed. These calculators exist to make that gap visible before you commit to a price — not after the money has already moved.
Pricing mistakes usually start with vocabulary. Margin and markup are not the same number: a 25% markup on cost yields only a 20% margin on price, and confusing the two systematically underprices everything you sell. The profit margin calculator works in both directions — from cost and price to margin, or backwards from a target margin to the exact price to charge. The freelance rate calculator applies the same backwards logic to your time: it starts from the income you need, subtracts realistic billable hours, expenses, and time off, and tells you the hourly rate that actually gets you there, which is reliably higher than the rate most freelancers guess. The commission calculator handles flat, tiered, and split structures so you can see your effective rate after every party takes its share.
Payment processor fees deserve their own set of tools because the math runs in the wrong direction for most people. Stripe, Square, and PayPal each charge a percentage plus a fixed fee, with surcharges for international cards and currency conversion stacked on top — so figuring out what to invoice in order to receive a specific net amount is not as simple as adding the percentage back. The Stripe and PayPal fee calculators do both the forward math (what will I receive?) and the reverse gross-up (what should I charge?), which matters every time a client agrees to cover the fees.
Beyond the calculators, the rent receipt generator produces a year of printable, signature-ready receipts from a single form — useful for landlords who need to issue proof of payment and tenants who need to document it. Like every tool on this site, these run as client-side code: the revenue figures, rates, and names you enter are processed locally on your device, never transmitted or stored, and there is no account to create.
Pricing & margins
Set prices and rates from the numbers that matter — target margin, target income, and your share after splits.
Profit Margin & Markup Calculator
Calculate profit margin and markup from cost and price — or work backwards from a target margin to the exact price you should charge.
Sales Commission Calculator
Calculate sales commission instantly — flat rate, tiered plans, and broker splits — with the effective rate and take-home after every cut.
Freelance Hourly Rate Calculator
Calculate your freelance hourly rate from target income, billable hours, expenses, and time off — and see your day rate and project pricing.
Payment processor fees
See exactly what Stripe, Square, and PayPal will take — and reverse the math to invoice the right gross amount.
Stripe & Square Fee Calculator
Calculate Stripe and Square fees and your net payout — standard, international, and currency conversion — plus reverse gross-up pricing.
PayPal Fee Calculator
Calculate PayPal fees for any amount and reverse the math — see exactly what to invoice so you receive your full target after fees and charges.
Documents
Generate printable business paperwork in your browser, ready to sign and hand over.
Guides
Margin vs. Markup: The Difference That Quietly Costs You Money
Markup is over cost, margin is over price. Confusing them under-prices your products. See the formulas, a conversion table, and why 25% markup is only 20% margin.
Stripe vs. PayPal Fees: What You Actually Keep
Stripe and PayPal both run about 2.9% + 30¢ on card payments, but the fixed fee guts small transactions. See how fees really work and how to price around them.
Frequently asked questions
Are receipts from the rent receipt generator legally valid?
A rent receipt is generally just a written record that payment was received — what makes it useful is accurate details (parties, property, amount, date, period) and the landlord's signature, not the software that printed it. The generator produces a complete, signature-ready document, but requirements for receipts and record-keeping vary by state and situation, so check your local rules or ask a professional if the receipt is needed for a legal or tax matter.
Are the Stripe and PayPal fee rates in these calculators current?
The calculators use each processor's published standard rates, including international and currency conversion surcharges, and they are updated when those rates change. Your account may have negotiated, nonprofit, or micropayment pricing that differs, so for invoicing decisions, confirm the rate on your own processor dashboard — the calculator lets you adjust the inputs to match.
What is the difference between margin and markup?
Markup is profit as a percentage of cost; margin is profit as a percentage of selling price. The same sale always has a higher markup than margin — a $100 cost sold at $125 is a 25% markup but only a 20% margin. Mixing them up is one of the most common small-business pricing errors, and the margin calculator displays both so the distinction stays visible.
Is the financial information I enter stored anywhere?
No. All calculations run in your browser on your own device. Revenue figures, commission structures, rates, and the names and addresses you put on a rent receipt are never uploaded, logged, or saved by the site, and you do not need to sign up for anything.
Can I rely on these calculators for taxes or official accounting?
Use them for what they are: fast, accurate arithmetic for pricing and planning decisions. They are not a substitute for your books, your accountant, or tax software — figures that end up on a tax return or in formal financial statements should be confirmed against your actual records and, where it matters, with a qualified professional.