conv.day — Instant Utility Calculators & Unit Converters
conv.day provides instant, client-side utility calculators, unit converters, and date planners designed for speed, privacy, and precision.
Date Difference Calculator
Calculate the exact number of days, working days, weeks, and months between two dates.
Working Days & Hours Calculator
Find out the exact number of workdays and working hours for any month or year.
Week Number Finder
Check the current ISO week number, dates, and total weeks for any given year.
Best Days to Take Vacation Planner
Find optimal vacation bridges to maximize consecutive days off using minimal annual leave.
Poland Salary Calculator (Gross to Net UoP)
Calculate your net salary from gross wage for Polish Employment Contract (UoP) with 12%/32% tax brackets, PIT-2, and 50% KUP (Copyrights).
VAT Calculator
Calculate VAT amounts and gross/net values.
Compound Interest Calculator
Estimate your investment growth over time.
Currency Converter
Live exchange rates and instant currency conversion with pre-calculated fast reference amounts.
Data Storage & Speed Converter
Convert between Bytes, KB, MB, GB, TB, PB and calculate download times.
Length & Distance Converter
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles.
Speed & Velocity Unit Converter
Convert between km/h, m/s, mph, knots, and Mach speed.
Weight & Mass Converter
Convert between kilograms, grams, milligrams, pounds, ounces, stones, and metric tons.
Temperature Unit Converter
Convert between Celsius (°C), Fahrenheit (°F), and Kelvin (K).
Area & Land Unit Converter
Convert between square meters, square kilometers, hectares, ares, acres, and square feet.
Download Time & Speed Calculator
Calculate how long it takes to download files of any size over various internet speeds.
Percentage & Margin Calculator
Calculate percentages, percent changes, discounts, and markup vs margin.
Mortgage & Loan Repayment Calculator
Calculate monthly payments, total interest, and amortization schedule for loans.
Time Zone Converter & World Clock
Convert date and time between major world time zones (UTC, EST, PST, CET, JST, AEST).
BMI, BMR & Calorie Calculator
Calculate your Body Mass Index (BMI), ideal weight range, and daily calorie needs (BMR/TDEE).
Medication Dosage & Syrup Calculator
Calculate precise single and daily medication dosage (mg/kg and liquid ml) based on body weight for children and adults.
About conv.day - Instant Utility Calculators & Unit Converters
conv.day is designed to deliver instant, client-side utility calculations without waiting for network round-trips. Powered by Astro and Cloudflare Edge Caching, all calculations are performed locally in your browser for maximum privacy and performance.
Why use conv.day?
Zero telemetry bloat, zero heavy framework lag, and instant recalculation on touch or keystroke.
🌍 Multilingual Support
Fully localized across English, Polish, German, Spanish, and French with dedicated canonical URLs.
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