General Calculators & Converters
Versatile tools for academic, study, and everyday calculations across subjects.
Age Calculator
Calculate exact age in years, months, and days
Annual Income Calculator
Calculate your annual income from hourly, weekly, monthly, or yearly pay.
Average Calculator
Calculate averages and weighted means from any set of numbers
Dice Roller & Probability Simulator
Roll dice, simulate outcomes, and explore exact probabilities with step-by-step explanations
Discount Calculator
Calculate final price, savings, and discount percent for any deal.
Dog Size Calculator (Puppy Size Predictor)
Estimate your puppy’s adult weight and height from age, size, and breed
Duration Calculator
Calculate the duration between two dates in years, months, and days
Earth Curvature Calculator
Calculate Earth curvature drop, hidden height, horizon distance, and clearance
Forgetting Curve Calculator
Estimate memory retention and plan optimal review timing
GPA Calculator
Calculate semester GPA, cumulative GPA, goal GPA, and retake impact with steps
Height Calculator
Convert height, compare, find differences, and predict adult height with steps
Lottery Tax Calculator
Estimate take-home lottery winnings after federal, state, and local taxes
Prime Factorization Calculator
Find prime factors, all divisors, and step-by-step work for any integer
ROI Calculator
Calculate ROI, annualized return, payback period, project ROI, and compare investments
Test Grade Calculator
Calculate your test grade or required final score with steps
Time Calculator
Calculate time between dates, add durations, or do HH:MM:SS math
Tip Calculator
Calculate tip, total, and per-person split (with tax, rounding, and amount mode)