Free calculators for pricing, business and savings
Work out margin, markup, discounts and VAT, check ROI, break-even and CPM, compare CD rates and APY, add up your net worth, and make UPC, EAN and Code 128 barcodes.
- Runs on your device, nothing uploaded
- No sign-up, no watermarks
- Works on phone and desktop
All tools
11 tools, all free, all private
Pricing
4 tools
Business
4 tools
Savings
3 tools
Popular shortcuts
One-click versions of the tools above
Why people use CentNook
Clear about the math
Margin next to markup, net next to gross, APY next to the rate: every answer shows the numbers people mix up.
Private by default
Prices, costs and balances stay on your device. Nothing is uploaded, and the net worth list is only saved if you choose.
Free, no sign-up
No accounts and no limits. Share any calculation with a link, or download your barcodes as PNG or SVG.
The numbers behind every sale
Pricing a product? The margin calculator and the markup calculator keep the two straight, the discount calculator shows what a sale really costs you, and the VAT calculator adds or strips out VAT. The barcode generator makes print-ready UPC, EAN and Code 128 codes.
For the business as a whole, check the ROI calculator, the break-even calculator and the CPM calculator for ad campaigns. Saving up? Compare offers with the CD calculator and the APY calculator, and track the big picture with the net worth calculator.
Frequently asked questions
Something else? Email hello@centnook.com.
Is CentNook free?
Yes. Every calculator and the barcode generator are free to use as often as you like. We are supported by ads, which we keep away from the tools themselves.
Is this financial or tax advice?
No. The calculators do the arithmetic and explain the usual rules, but they are not advice for your situation. For tax, investments and business decisions, check with an accountant or a licensed adviser.
Can I use the barcodes on products I sell in stores?
The barcodes themselves are standard and print-ready. But retailers usually require UPC and EAN numbers that are licensed to your company by GS1, so get your numbers from GS1 before you print retail packaging.