Plans and credits
Every plan includes every calculator, over the REST API and MCP. Plans differ in monthly credits, the per-minute request limit and the number of API keys. Calculations in the browser are free.
You can cancel a plan at any time and keep it to the end of the period you paid for. Before you pay, read Cancellation and refunds.
Top-up credits
One-time packs for any plan, including Free. Top-up credits are used after your monthly credits.
Compare plans
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Questions
What is a credit?
Each API or MCP calculation costs credits by kind: maths, business, and tax, loan and savings calculations (the ones that use dated official figures) cost different amounts, shown on the plan cards above. Plan credits reset every month. Top-up credits are used after plan credits.
Is a refused calculation charged?
No. When a calculation needs a fact you did not give, or a rule set has expired, the answer names what is missing and no credits are used.
What happens when I run out of credits?
Calls are refused until your monthly credits reset. There are no overage charges: buy a top-up or move to a larger plan to continue.
What does the per-minute limit mean?
It is the most requests one account can make in a minute. Higher plans allow more, for agents that call many tools at once.
Can I move to a larger plan?
Yes, at any time, from the Subscriptions page. You pay the price difference for the rest of the current billing period, and the extra credits for the rest of the month are added at once. See the Terms.
How do I cancel?
Yourself, at any time: open Subscriptions and choose Manage billing. Your plan stays active to the end of the period you paid for. See the Refund and Cancellation policy.
Are taxes included?
Prices are in US dollars and before tax. Tax for your country (GST in India, VAT in the EU and UK, sales tax where it applies) is added at checkout and shown before you pay: see Billing, taxes and your country.
Need more than Scale?
Email us with your expected monthly volume.