Pricing

Simple, one-time pricing

Pay once, unlock forever. Your license key is delivered to your email instantly after payment — no account, no subscription, no renewal.

Free

forever · no card needed

15 essential calculators for everyday tasks. No sign-up required.

Most popular

CalcPro

one-time · key by email instantly

Financial and health tools for serious planners and everyday professionals.

CalcExpert

$10

one-time · all 55 calculators

Every calculator on the site — advanced finance, statistics, and engineering.

🔒 Payments secured by Stripe · Key delivered to your email within seconds · Lost your key? Retrieve it here · Questions? hello@digitalcalculus.com

Frequently asked questions

How do I get my license key after paying?

Instantly — two ways. It appears on the confirmation page right after payment, and it's also emailed to the address you enter at Stripe checkout.

How do I activate my key?

Click "Unlock Pro / Expert" in the top navigation on any page, paste your key, and click Unlock. Access is saved in your browser — no login needed.

What if I lose my key?

Go to our key retrieval page, enter the email you used to pay, and your key will be shown on screen and resent immediately.

Does this work on all my devices?

Yes — paste your key into the unlock box on any browser or device you want to use. Access is stored locally in that browser.

Is this a subscription?

No. One-time payment, permanent access. No renewals, no monthly charges.

Can I upgrade from Pro to Expert?

Yes — purchase CalcExpert and use the new key. Email hello@digitalcalculus.com for a $5 upgrade discount.