About Calc Tools

Calc Tools is a free, open-access collection of 7 utilities built for speed and privacy. Every tool runs entirely in your browser — no data is ever sent to our servers, logged, or stored.

Our Philosophy

• Local-first: All computation happens on your device using browser APIs.
• No login required: Open a tool, use it, done.
• No tracking of inputs: Your data stays on your machine.
• Fast: Static pages with no server round-trips.

Available Tools

• Percentage Calculator — Calculate percentages: X% of Y, what % is X of Y, percentage change.
• BMI Calculator — Calculate Body Mass Index from height and weight (metric and imperial).
• Age Calculator — Calculate exact age in years, months, and days from any birthdate.
• GPA Calculator — Calculate GPA from course grades and credit hours.
• Grade Calculator — Convert scores to letter grades and calculate weighted averages.
• Aspect Ratio Calculator — Calculate aspect ratios and scale dimensions proportionally.
• Tip Calculator — Calculate tip amount and split the bill between multiple people.

Quality Policy

Each tool is tested against common edge cases. We prioritize correctness over feature bloat. If you find a bug, please contact us so we can fix it promptly.