All Tools

Calculate percentages instantly with 5 different modes: find X% of Y, what percent X is of Y, increase/decrease values, percent change, and percent difference.

Add, subtract, multiply, and divide fractions with automatic simplification. Supports mixed numbers and shows step-by-step solutions.

Calculate with extremely large numbers beyond normal limits. Supports addition, subtraction, multiplication, division, powers, roots, factorial, GCD, and LCM with arbitrary precision.

Randomly divide participants into teams, create pairs, assign roles, or generate seating arrangements with just one click.

Generate random lottery numbers for Powerball, Mega Millions, EuroMillions, VietLott, and 50+ lottery games worldwide. Quick picks in seconds.

Make fair random selections with a customizable spinning wheel. Perfect for lucky draws, giveaways, classroom activities, and decision making.

Roll virtual dice online — D4, D6, D8, D10, D12, D20, D100, or custom. Animated 3D dice, sound effects, and roll history.

Generate random integers, decimals, or percentages within any range. Customize with step, filter, sort, and no-duplicate options.

Browse public holidays for 199 countries. Filter by holiday type, navigate years, and see the next upcoming holiday at a glance.

Calculate sunrise, sunset, day length, golden hour, and twilight times for any location worldwide.

Calculate your pregnancy due date based on your last period, conception date, or known due date. Track pregnancy progress and key milestones week by week.

View solar and lunar dates side by side with traditional almanac details including Can Chi, zodiac, solar terms, and auspicious hours.