Everyday answers, in 38 free calculators

Money, salary, units, dates, AI costs — every tool runs instantly in your browser. No sign-up, and your numbers never leave your device.

AI Cost Intelligence

Specialized

Our deep-dive suite — live pricing, real budgets, real decisions.

AI & Dev Tools11 tools · in-depth Money & Loans4 calculators Salary & Work3 tools Unit Conversion2 tools Everyday Math3 calculators Dates & Time3 calculators Health1 calculator Images9 tools PDF & Documents3 tools Text & Security6 tools

Money & Loans

🏠Mortgage Calculator

Full PITI payment, amortization schedule, and extra-payment savings.

💳Loan Calculator

Monthly payment and total interest for any personal or auto loan.

📈Compound Interest

How savings grow with monthly contributions and compounding.

🏷️Discount Calculator

Sale price and savings — including stacked "extra % off" deals.

Salary & Work

💼Salary to Hourly

Your true hourly rate — with real hours and vacation weeks.

🧾Take-Home Pay (2026)

Salary after federal tax, FICA, 401(k), and state tax.

📋Salary Breakdowns

Every salary from $25k to $300k, per hour, week, and month.

Unit Conversion

🔁Unit Converter

Length, weight, temperature, volume, area & speed in one tool.

📐Conversion Reference

Every factor at full precision — length, weight, volume, area, speed, temperature.

AI & Developer Tools

🤖AI API Cost Calculator

Compare GPT, Claude & Gemini pricing and estimate your bill.

💠AI Pricing by Provider

Every tracked model priced and compared within its provider lineup.

Everyday Math

Percentage Calculator

X% of a number, percent of Y, and increase/decrease.

🍽️Tip Calculator

Tip, total, and per-person share when splitting the bill.

🛒Discount Calculator

What you actually pay after the sale sticker.

Dates & Time

📅Date Calculator

Days between dates (with business days), add/subtract days.

🎂Age Calculator

Exact age in years, months, days — plus next-birthday countdown.

Health

⚖️BMI Calculator

Body mass index in metric or US units, with healthy range.

Images

✂️Background Remover

AI cutout to a transparent PNG — your photo never leaves your browser.

🖼️Image Compressor

Shrink JPG/PNG/WebP file size in your browser — nothing is uploaded.

🔄Image Converter

HEIC to JPG, WebP to PNG — convert between formats locally.

🕵️EXIF Viewer & Remover

See hidden GPS and camera metadata in photos — and strip it out.

Crop for Social Media

YouTube thumbnail, Instagram, and profile-circle presets with drag & zoom.

Favicon Generator

One image to every favicon size plus a real .ico — zipped.

💧Watermark Tool

Add a text or logo watermark to photos — corners or tiled.

📄Image to Base64

Data URI generator with ready-made HTML and CSS snippets.

Round Corners & Circle

Rounded corners or circle crop to a transparent PNG.

PDF & Documents

📎Merge PDF

Combine several PDFs into one, in the order you choose — no upload.

🖼️JPG to PDF

Turn photos and images into a single PDF document.

✂️Split PDF

Extract a page range, or save every page as its own PDF.

Text & Security

✍️Word Counter

Live word, character, sentence counts and reading time.

🔐Password Generator

Strong random passwords, generated locally in your browser.

QR Code Generator

Any link or text to a downloadable QR code — all in your browser.

🔗URL Shortener

Turn a long link into a short, shareable one — free, no sign-up.

🔠Case Converter

UPPERCASE, lowercase, Title Case, camelCase, snake_case in one click.

⏱️Timestamp Converter

Unix epoch time to readable date and back — live current timestamp.

🆚Diff Checker

Compare two texts line by line and see exactly what changed.

Guides

⏱️Unix Time for Beginners: What a Timestamp Actually Is

Unix time is just a number of seconds — no dates, no timezones. Why software uses it, why seconds vs. milliseconds breaks things, and what the Year 2038 problem is.

💧Should You Watermark Your Photos? A Practical Guide

Watermarks protect some photos and hurt others. When adding one actually helps, when it backfires, and how to place one without ruining the shot.

🔖Favicons, Fully Explained: Every File and Fix You Need

The favicon files browsers, iOS, Android, and Google Search actually check for in 2026, and why favicons silently fail to update.

⚖️Is ChatGPT Plus Worth It? Subscription vs. API, By the Numbers

ChatGPT Plus, Claude Pro, and Gemini Advanced cost about $20/month flat. Who actually comes out ahead paying per token instead, and who shouldn't bother.

💾Prompt Caching Explained: How to Cut Your AI API Bill

Prompt caching lets you pay a fraction of the price for tokens you send repeatedly. How OpenAI, Anthropic, and Google implement it, and when it actually saves money.

🔤AI Tokens Explained: What They Are and Why You're Billed on Them

AI models don't charge by the word or the API call — they charge by the token. What a token is, why it's the billing unit, and how to use fewer of them.

All guides → · RSS

Last reviewed: · Who maintains this · How it is checked

Every tool listed here runs in your browser — no uploads, no accounts, nothing leaving your device — with a single disclosed exception, the URL shortener, which has to send the address you paste to the service that stores the redirect. The figures behind the calculators come from primary sources (IRS, SSA, NIST, and each AI provider's own pricing page), and the build refuses to publish if any two pages quote the same number differently.