Calculator Tools
Free online calculators — math, date/time, and academic calculators for percentages, fractions, date differences, grade averages, and more. 100% browser-based.
About Calculator Tools
Online calculators for percentages, fractions, dates, grades, and everyday math — EMI-style precision without the signup. Every calculation runs in your browser; results appear as you type, and nothing you enter is ever sent to a server.
Percentage Calculator
Computes X% of Y and what-percent-of-what (X is what % of Y) in two side-by-side panels with precise decimal arithmetic. Essential for everyday math — tips, discounts, tax rates, grade scores, and statistical comparisons where quick percentage answers are needed.
Exponent Calculator
Raise any base to any power — squares, cubes, negative and fractional exponents with full precision. Students check 2^10 = 1024 homework in seconds — free, no signup, runs locally.
Fraction Calculator
Add, subtract, multiply, and divide fractions with simplification and decimal equivalents. Split 3/4 of a bill three ways without decimal drift — free, runs locally.
Fraction to Decimal Calculator
Convert a Numerator/Denominator fraction to a 6-place decimal with percent and equivalents. Shows the decimal result directly. Numbers never leave your device — every calculation runs locally in your browser.
Ratio Calculator
Simplify any two-number ratio to lowest terms via GCD — paint mixes, screen sizes, shares. Reduce 150:225 to 2:3 in one pass — free, runs locally.
Probability Calculator
Compute simple probability as favorable outcomes divided by total outcomes — coin flips, dice rolls, card draws. See 3 in 10 read as 30.0% instantly — free, local, no signup.
Combination Calculator
Compute nCr combinations and nPr permutations with factorial steps shown. Count 5-card poker hands (2,598,960) correctly — free, local, no signup.
Prime Number Checker
Check if any number is prime. Also shows all factors and whether the number is odd or even. Numbers never leave your device — every calculation runs locally in your browser.
Greatest Common Factor Calculator
Find the greatest common factor (GCF/GCD) of number sets via Euclidean algorithm with steps. Reduce 48:180 to 4:15 correctly — free, local, no signup.
Modulo Calculator
Calculate the remainder of division (a mod b). Shows quotient, remainder, full division expression, and negative dividend semantics. Numbers never leave your device — every calculation runs locally in your browser.
Mean Median Mode Calculator
Compute mean, median, and mode for any dataset with distribution insight. See why averages mislead skewed data — free, local, no signup.
Quadratic Equation Solver
This quadratic equation solver handles ax²+bx+c=0 with roots and discriminant shown — real, repeated, or complex. Check x²−5x+6=0 gives 2 and 3 before submission — free, runs locally.
Circle Calculator
Compute circle area and circumference from the radius — geometry homework solved. Enter r=5 and read both measures at once — free, local, no signup.
Aspect Ratio Calculator
Get any image or screen's aspect ratio in reduced form with common-ratio matching — 16:9, 4:3, 1:1 and custom. Check a 1920×1080 screen reads 16:9 — free, runs locally.
DPI Calculator
Compute display DPI from pixel width, pixel height, and diagonal inches — diagonal pixels over diagonal size. Compare phone and laptop sharpness honestly — free, runs locally.
Scientific Calculator
Evaluate mathematical expressions with sin, cos, tan, log, and sqrt functions. A versatile scientific calculator in your browser. No signup or account required.
Degree / Radian Converter
Convert degrees and radians both ways with π-exact forms — 180° = π rad. Stop mixing modes in calculus — free, local, no signup.
Significant Figures Calculator
Round results to correct significant figures with rule explanations — 0.00450 has 3. Stop overstating lab precision — free, local, no signup.
Gas Mileage Calculator
Calculate gas mileage as MPG (miles per gallon) from distance driven and fuel consumed, with a metric L/100km view and trip-cost math. Numbers never leave your device — every calculation runs locally in your browser.
Percentage Difference Calculator
Calculate the percentage difference between any two numbers. Useful for comparing data sets, prices, and measurements. Numbers never leave your device — every calculation runs locally in your browser.
Algebra Calculator
Evaluate arithmetic algebra expressions with + − × ÷, parentheses and decimals — digits-only evaluator, no variables. Check homework before class — free, local, no signup.
Geometry Calculator
Solve geometry essentials — areas, perimeters, volumes, angles — with diagrams described. Cover homework shapes in one tab — free, local, no signup.
Slope Calculator
Compute line slope from two points with intercept form — rise over run done right. Get m and b for graphing — free, local, no signup.
Math Equation Solver
Solve linear equations step by step — isolate x with operations shown. Check 3x + 7 = 22 → x = 5 before class — free, local, no signup.
Screen Size Calculator
Convert screen sizes between inches, cm, resolution, and aspect — compare displays honestly. Check a 27-inch 4K pixel density — free, local, no signup.
Proportion Calculator
Solve proportions a/b = c/d for the fourth term — recipes, maps, dosages scale correctly. Double a 4-serving recipe to 10 without breaking ratios — free, runs locally.
PPI Calculator
Compute screen pixel density from resolution and diagonal size — compare phone sharpness honestly. A 1080p 6-inch display gives ~367 PPI — free, runs locally.
Pythagorean Theorem Calculator
The Pythagorean theorem solves c = √(a²+b²) for the hypotenuse from two legs — ladders, ramps, screen diagonals. A 3-4-5 triangle reads c = 5.00 on site — free, runs locally.
Rectangle Area Calculator
Compute rectangle area and perimeter from length and width — flooring, paint, fencing estimates. A 12×15 ft room needs 180 sq ft of flooring — free, runs locally.
Square Root Calculator
Compute square roots to four decimals — verify √144 = 12.0000 and spot irrational results instantly. Free, runs locally.
Standard Deviation Calculator
Compute population and sample standard deviation with variance, mean, median, and range for any dataset — exam scores, lab readings, quality checks. A class scoring 70±8 reads spread at a glance — free, runs locally.
Decimal to Fraction Calculator
Convert decimals to exact fractions — 0.75 to 3/4 with repeating-decimal support. Get exact answers for homework — free, local, no signup.
Permutation Calculator
Calculate the number of ways to arrange k items from n items (nPr). Shows the step-by-step permutation calculation. Numbers never leave your device — every calculation runs locally in your browser.
Factorial Calculator
Calculate the factorial of any number (n!). Handles large numbers and shows the full multiplication sequence. Numbers never leave your device — every calculation runs locally in your browser.
Prime Factorization Calculator
Break any integer into prime factors with factor trees — 60 = 2²×3×5 shown stepwise. Ace number theory homework — free, local, no signup.
Least Common Multiple Calculator
Find LCM of number sets for scheduling cycles and fraction denominators. Sync 4-day and 6-day rotas every 12 days — free, local, no signup.
Logarithm Calculator
Compute logarithms (logs) in any base with change-of-base steps and natural/common presets. Solve log₂(32) = 5 instantly — free, local, no signup.
Trigonometry Calculator
Compute trigonometry: sin, cos, tan in degrees or radians with triangle solving. Find the opposite side from 30° hypotenuse 10 (= 5) — free, local, no signup.
Scientific Notation Converter
Convert between standard and scientific notation — 6,020,000,000 ↔ 6.02×10⁹. Handle Avogadro-scale numbers cleanly — free, local, no signup.
Rounding Calculator
Round numbers using 5 modes: round half up, banker's rounding, floor, ceil, and truncate. Shows step-by-step explanation with the digit being rounded. Numbers never leave your device — every calculation runs locally in your browser.
Coordinate Calculator
Compute distance, midpoint, and slope between coordinate points — geometry essentials. Get all three from two points — free, local, no signup.
Triangle Area Calculator
Calculate triangle area three ways — base and height, three sides (Heron), or two sides plus included angle. Pick the method matching your knowns. Numbers never leave your device — every calculation runs locally in your browser.
Age Calculator
Computes exact age in years, months, and days from a given birth date relative to any target date. Numbers never leave your device — every calculation runs locally in your browser.
Business Days Calculator
Count working days between two dates excluding weekends — HR teams prorate leave and payroll accurately. A 20-day leave request spans 28 calendar days — free, no signup, runs locally.
Day of Week Calculator
Find the weekday for any Gregorian date — plan anniversaries, verify old records, settle bets. Check what day you were born in seconds — free, no signup, runs locally.
Day of Year Calculator
Convert any date to its day-of-year number (1–365/366) with days remaining. Developers compute ordinal dates for logs and filenames — free, no signup, runs locally.
Leap Year Calculator
Test any year for leap status with the full Gregorian rule — divisible by 4, except centuries unless divisible by 400. Settle the 1900 vs 2000 debate instantly — free, runs locally.
Time Until Calculator
Count down the time until any future moment in days, hours, minutes, and seconds — launches, deadlines, events. See 45 days to launch live — free, local, no signup.
Date Difference Calculator
Measure the exact gap between two dates in days, weeks, and months — tenures, ages, project spans. A 3-year job stint reads 1,096 days instantly — free, no signup, runs locally.
Week Number Calculator
Get ISO week numbers for any date — plan sprints and fiscal weeks correctly. Know Week 32 means late July instantly — free, local, no signup.
Work Hours Calculator
Calculate total work hours for a single shift between start and end times with one configurable break. Essential for timesheets and payroll. Numbers never leave your device — every calculation runs locally in your browser.
ETA Calculator
Estimate travel time from distance and speed — with optional arrival time and traffic buffer. Add traffic buffers and arrival targets for realistic plans — free, local, no signup.
Time Duration Calculator
Calculate the exact duration between two times. Handles overnight time spans and displays results in hours, minutes, and seconds. Numbers never leave your device — every calculation runs locally in your browser.
Time Addition Calculator
Add hours and minutes to any time — shift schedules, compute end times, total durations. Add 8h30m to 9:00 for shift end — free, local, no signup.
Meeting Time Planner
Find meeting slots across attendee time zones with working-hours overlap. Schedule standups spanning continents fairly — free, local, no signup.
Date Addition Calculator
Add or subtract days, weeks, months, and years from any date — calendar-accurate. Find 100 days from hire date exactly — free, local, no signup.
Time Since Calculator
Measure exact elapsed time since any moment — days, hours, minutes live. Track 100 days sober to the second — free, local, no signup.
DST Checker (US)
Check DST observance and transition dates for any timezone — spring forward dates decoded. Never miss a global meeting again — free, local, no signup.
Hours & Minutes Calculator
Add and subtract hours:minutes durations — timesheets, shifts, project totals. Sum 7:30 + 8:15 correctly — free, local, no signup.
Final Grade Calculator
Compute your overall course percentage from comma-separated assignment grades and their matching weights — Exam Heavy presets included. Numbers never leave your device — every calculation runs locally in your browser.
GPA Calculator
Compute semester GPA from course grades and credit hours with credit-weighted math on the standard 4.0 scale — quick academic snapshot. See what straight B's earn — free, local, no signup.
Grade Calculator
Convert a single course percentage into its letter grade on the built-in plus/minus scale — see that an 85 earns a B instantly. Free, local, no signup.
College GPA Calculator
Compute semester GPA from course grades and credit hours with weighted math. Students check what an A in a 4-credit lab does before finals — free, no signup, runs locally.
Study Time Calculator
Plan study hours from syllabus weight and days left — pass with scheduled effort. Turn 5 chapters in 10 days into daily targets — free, local, no signup.
Test Score Calculator
Compute test percentages and grades from correct/total with curve options. Turn 42/50 into 84% (B) instantly — free, local, no signup.
Words Per Page Calculator
Estimate pages from word count and font size — about 500 words/page at 12pt, 600 at 10pt and under. Font-size-only math, no spacing or margin inputs — free, local, no signup.
More from Toolzum
✓ 66 calculators, every formula computed locally with steps shown.
Works fully offline after first load — nothing leaves your browser.
Calculator FAQs
How do I calculate a percentage increase?
Subtract old from new, divide by old, multiply by 100. Going from 40 to 50 is a 25% increase — the percentage calculator handles increase, decrease, and reverse-percentage in one place.
How are weighted grades averaged?
Multiply each score by its weight, sum those products, and divide by total weight. A 90 on a 60%-weighted exam plus 70 on 40% coursework averages 82, not 80.
How do I count days between two dates?
Enter both dates to get exact days, weeks, and months between them — useful for notice periods, warranties, and age calculations. Results account for leap years automatically.
Are the calculations precise for money?
Yes — decimal math avoids the floating-point errors that make 0.1 + 0.2 equal 0.30000000000000004 in spreadsheets. Financial figures round correctly to paise and cents.