Small business math, solved.

Free calculators for pricing, payroll, invoices, taxes and loans. Every one shows its formula and a worked example.

9 free calculators2026 tax figures0 sign-ups required

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🧾InvoicingGet paid on time

Invoice Late Fee CalculatorWork out what a client owes on an overdue invoice, including monthly interest and a flat late charge.

🏷️PricingCharge the right amount

Markup and Margin CalculatorTurn a cost into a selling price, or see the real margin behind a markup. Margin and markup are not the same number.Freelance Hourly Rate CalculatorFigure out what to charge per hour so your freelance business covers taxes, expenses and time off.

👥PayrollPay your people

Paycheck CalculatorEstimate an employee's net pay per paycheck using 2026 federal tax brackets and FICA rates.

🏛️TaxCollect and plan for tax

Sales Tax CalculatorAdd sales tax to a pre-tax price, or work backward from a total that already includes tax.

🏦FinancingBorrow with confidence

Business Loan Payment CalculatorSee the monthly payment and total interest on a business, equipment or SBA loan, with a full amortization schedule.

📈PlanningKnow your numbers

Break-Even Point CalculatorFind out how many units you need to sell before your business starts making a profit.Profit Margin CalculatorMeasure gross, operating and net profit margins from your revenue and costs.Startup Cost CalculatorAdd up one-time launch costs and months of operating expenses to estimate how much cash you need to open.

Why owners use TallyKit

Show the math

Every calculator explains its formula and includes a worked example you can check by hand.

Private by design

Calculations run in your browser. The numbers you type are never sent to us.

Kept current

Tax brackets, wage bases and deductions are updated when the IRS publishes new figures.