Pro: frequently asked questions

All calculators stay free, with no ads, no tracking and no sign-up. Pro adds:

• The full BOM tool: whole-device cost per board and per batch, unlimited rows and paste-import from a spreadsheet. (The free version covers up to 3 rows, with cost and battery totals for those rows.)
• A battery-life summary that adds up every part's active and sleep current.
• PDF and CSV export of any result. The PDF is a clean sheet without the Ohmlark footer.
• Saved projects, kept in this browser. Export them to CSV to back them up.
• Priority email support.

Printing is free for everyone: the Print button prints any result with a small Ohmlark footer and a link back to the calculator.

Pro Monthly is $4 per month. It renews automatically each month until you cancel, and you can cancel at any time.

Pro Lifetime is a one-time payment of $29 for access for as long as Ohmlark is operated, including all future Pro features. If you expect to use Pro for more than about seven months, Lifetime costs less.

Prices are in USD. Taxes may apply and are calculated at checkout by Creem, our Merchant of Record.

Ohmlark has no accounts. Your Pro access is tied to a license key.

• After checkout you return to Ohmlark, Pro is switched on in that browser, and the key is shown on the page.
• Creem, our Merchant of Record, emails the receipt and license key to the address you entered at checkout.
• In a browser that has Pro, the key is also shown on your account page.
• On a new device or browser, open ohmlark.com/restore and paste the key.

Keep the key somewhere safe. You need it to use Pro in another browser.

Yes. Your license is personal and you may use it on your own browsers and devices. Open ohmlark.com/restore in the other browser, paste your license key and select Unlock Pro.

Pro is remembered with a single cookie in each browser. If you clear cookies or site data, or use a private window, enter your key again on the restore page. Saved projects are stored in the browser too, so export them to CSV before you clear site data.

Each key can be activated in a limited number of browsers. Unlocking Pro again in a browser that already used the key does not use up another activation, and Remove Pro from this browser on the account page releases that browser's activation so you can use it elsewhere. If a key will not activate, email hello@ohmlark.com with the key or your order email and we will sort it out.

Sharing or reselling license keys is not allowed. Keys that are shared publicly may be revoked.

Open your account page in a browser that has Pro and select Manage billing. It opens the customer portal of Creem, our Merchant of Record, where you can cancel, update your card and download invoices. The account page also shows your next renewal date. Creem's receipt email has a link to the same portal.

If the button does not work, or you no longer have Pro in any browser, email hello@ohmlark.com from your order email (or include your license key) and we will cancel it for you. Cancelling stops future renewals. You keep Pro until the end of the period you have already paid for.

Lifetime is a one-time payment, so there is nothing to cancel.

Yes, within 14 days of your first payment, for either Monthly or Lifetime. Email hello@ohmlark.com with your order email or license key and we will issue a full refund, no questions asked.

• Refunds are issued by Creem to your original payment method and usually appear within 5 to 10 business days, depending on your bank.
• When a refund is issued, the Pro access and license key for that purchase are deactivated.
• Monthly renewal payments are generally not refunded, except where required by law or where a charge was clearly made in error.

See the full refund policy.

Email hello@ohmlark.com. This includes a payment that went through but Pro did not unlock, a key that will not activate, a wrong charge, invoice questions, or a result you think is wrong. Include your order email or license key for anything about a purchase. Never send your card details.

Payments, taxes and invoices are handled by Creem, our Merchant of Record, which also stores your billing details under its own privacy policy. Ohmlark receives only what it needs to provide Pro: an order ID, product, subscription status and renewal date, your email and your license key. Invoices are available from Manage billing on your account page. See the privacy policy.