Why this site exists
Pricing pages for payment providers and AI platforms are full of percentages, fixed fees, footnotes and exceptions. Turning them into a simple answer “what will I actually receive?” or “what will this cost per month?” usually means a spreadsheet. SmartCalcWorks does that arithmetic for you and shows exactly how it got there.
Who builds it
SmartCalcWorks is an independent project based in Aotearoa New Zealand, built by Raycart Ore a payments and technology delivery professional with more than 20 years’ experience in banking and payments transformation across the Asia-Pacific region. The calculators reflect the questions that come up again and again when businesses set up card payments, price their services and plan technology costs.
How we keep the numbers honest
- Formulas are published on every calculator page, with worked examples you can check by hand.
- Fee and price presets come from official sources. Each shows the provider’s page and the date we last checked it. If we can’t verify a figure, we don’t include it as a preset you can enter your own instead.
- Limitations are stated plainly. Real fees depend on your account, card type, country and pricing terms, and we say so.
- Calculation logic is tested with automated tests covering normal cases, edge cases and rounding.
Independence
SmartCalcWorks is not affiliated with, sponsored by or endorsed by Stripe, PayPal, Inland Revenue, Anthropic, OpenAI, Google or any other company mentioned on the site. Product names are used only to identify the services the calculators relate to.
How the site is funded
The calculators are free. In future the site may display advertising to cover running costs. Any advertising will be clearly separated from calculator results and will never influence the numbers.
Calculators
- Stripe Fee Calculator — Estimate Stripe processing fees and net payout, or work backwards to the amount to charge so you receive what you need.
- PayPal Fee Calculator — Calculate PayPal commercial transaction fees for domestic and international payments, and the amount to invoice for a target net.
- New Zealand GST Calculator — Add 15% GST to a price or extract GST from a GST-inclusive amount, with an adjustable rate.
- Profit Margin Calculator — Find gross profit, margin and markup from cost and selling price, or the price needed to hit a target margin.
- AI API Cost Calculator — Estimate AI API costs from input and output tokens, request volume and per-million-token prices for popular models.
Spotted a mistake?
If a fee has changed or a result looks wrong, please get in touch. Corrections are the most valuable feedback we receive.