Simple, honest pricing

One product. One price. No subscriptions to keep using the version you already bought.

LIFETIME LICENSE

$200

One-time payment. Yours forever.

✓Unlimited worksheets
✓Desktop app for Windows, macOS, and Linux
✓Offline-capable after activation
✓AI assistant with your own API key
✓PDF, DOCX, and HTML export
✓Solve goals and system analysis
✓Templates library
✓3 machine activations
✓Free updates for life

30-day money-back guarantee

Perpetual license

You buy the desktop app once, keep it forever, and receive ongoing updates without a renewal fee.

Readable files

Worksheets are local JSON files, and you can export them to PDF, DOCX, or HTML whenever you need a handoff artifact.

Simple activation

Each key activates on up to 3 machines, and you can move a seat by deactivating one device and activating another.

Low buyer risk

30-day money-back guarantee and direct support from the same team that builds the product.

Compare the tradeoff, not a shaky price scrape

Pricing and plan structures move around. The operational differences do not. This comparison keeps the value proposition on defensible ground.

Question

Subscription math tools

Spreadsheet workflow

ProveCalc

Billing model

Usually annual subscription or seat-based renewal.

Already owned, but labor-intensive and hard to review.

$200 one-time desktop license.

Traceability

Varies by product and workflow.

Manual and easy to lose in formulas or hidden cells.

Worksheet-native audit trail with visible intermediate steps.

File ownership

Often tied to product-specific formats or vendor lifecycle.

Portable, but logic is fragile and easy to separate from context.

Local JSON plus export to PDF, DOCX, and HTML.

Offline use

Depends on licensing and deployment model.

Yes, but without built-in verification.

Desktop app runs offline after activation.

AI workflow

Vendor-specific or unavailable.

Usually external add-ins or manual prompting.

Optional BYO key. AI drafts structure, engine computes.

Frequently asked questions

Is this really a one-time payment?

Yes. You pay $200 once, own the desktop license forever, and updates are included for life.

What does 'bring your own key' mean for AI?

You choose and pay for the AI provider directly. ProveCalc sends prompts to that provider only when you use AI features, and the AI never performs the actual calculation.

Can I use it offline?

Yes. The desktop app works offline after initial activation. Core calculations, files, and exports do not need an internet connection.

What happens to my files over time?

Your files stay on your machine as JSON and remain exportable. Updates do not change ownership of your worksheets, and there is no renewal gate on access to your existing work.

Do you offer refunds?

Yes. Every desktop license comes with a 30-day money-back guarantee.