Business
Invoicing, margin & GST calculators
Business calculators
13 tools for Invoice total, Margin, GST and more — accurate, instant, and free.
Reckonist’s Business calculators turn day-to-day commerce maths into clear figures — invoice and GST totals, profit margin and mark-up, break-even, and price-with-tax. Each one runs on a source-cited engine with the current GST rates built in, free and with no sign-up, computing in your browser so your numbers never leave your device.
Invoicing & tax4
Invoice Generator
Create a compliant invoice and download it as a PDF, free and with no sign-up — a GST tax invoice (India, Rule-46), a VAT invoice (UK, HMRC), or a plain invoice (US) — plus estimates, quotes, receipts and purchase orders.
GST Calculator
Add, reverse & split GST (CGST/SGST/IGST) at current GST 2.0 rates.
VAT Calculator
Add or remove VAT at UK & EU rates — 20%/5%/0% and more.
Sales Tax Calculator
Add or reverse US sales tax by state (combined state + avg local).
Pricing & margin5
Markup Calculator
Convert between markup and margin; price from cost + markup or target margin.
Profit Margin Calculator
Gross, operating & net profit margin — plus the price for a target margin.
Discount Calculator
Percent-off, fixed-off, stacked & reverse discounts — and discount-then-tax.
ROI Calculator
Simple & annualized ROI, ROAS and marketing ROI, payback period.
Break-Even Calculator
Break-even units & revenue, contribution margin, target-profit units and margin of safety.
Payments & payroll4
Payment Processor Fee Calculator
Stripe, PayPal & Square fees — net after fee, gross-up, and side-by-side compare.
Commission Calculator
Flat, tiered (graduated), base-plus, real-estate split & draw commission.
Time Card Calculator
Clock in/out + breaks → daily & weekly hours, overtime and gross pay.
Tip Calculator
Tip amount, bill split, round-up and pre/post-tax tipping.