BriskToolbox — Free Offline Calculators

65 calculators for loans, savings, health and online selling. Works offline. No account, no tracking, no permissions.

Sixty-five calculators, one click away, working whether you are online or not. Open the popup, type two or three letters, press Enter. The calculator opens in place: no new tab, no page load, no waiting for a website to answer. WHAT IS IN IT Loans and mortgages (28) — monthly payment, full amortization, extra payments, refinance, affordability, debt-to-income, auto, student, business, home equity and more. Savings and investing (9) — compound interest, retirement, 401(k), Roth IRA, certificates of deposit, savings goals. Health and fitness (16) — BMI, BMR, calories and TDEE, macros, body fat, ideal weight, due date, ovulation, pregnancy weight gain, water intake, heart-rate zones, caffeine, sweat rate. Seller tools (9) — Amazon FBA, eBay, Etsy, TikTok Shop and Walmart Marketplace fees, break-even ROAS, inventory turnover, profit margin. Everyday maths (3) — discount, sales tax, return on investment. IT ASKS FOR NOTHING No permissions. None. It cannot read the pages you visit, your history or your tabs, because it never asks for access to them — check the install dialog and you will see it request nothing at all. No account, no sign-up, no analytics, no advertising, and nothing leaves your machine. The calculators and everything they need are inside the extension, so it works on a plane, on the underground, and with the Wi-Fi off. The only thing it remembers is which language you chose, in your own browser. THREE LANGUAGES, THREE SETS OF TOOLS English (65), Spanish (72) and Portuguese (29). These are not translations of one list. Spanish adds Mexican, Colombian, Spanish and Argentine payroll; Portuguese works in reais against Brazilian references. Switch with the flags at the top of the popup. WHEN YOU WANT MORE THAN THE NUMBER Every calculator links to the same one on brisktoolbox.com, where you get the full amortization schedule, the charts, the sources behind the figures and an explanation of the method.