Online Calculators & Tools

Evaluates limits of rational functions exactly: at a point by dividing out (x - a), and at infinity by comparing degrees and leading coefficients.

Split revenue into gross, operating and net profit using cost of goods sold, operating costs and tax, or work the same margins up from unit price and cost.

Works out frames per second from a frame count and a capture time, turns a frame rate into a frame time in milliseconds, and sets it against a refresh rate.

Adds, subtracts, multiplies and divides lengths written in feet and inches, giving the answer back in feet and inches to the nearest sixteenth.

Factors a whole number into every divisor and its prime powers, or factors a one-variable polynomial up to degree 4 into linear factors.

See the down payment, closing costs and total cash a home purchase needs, or turn the savings you already have into the price they would cover.

Estimates the theobromine and caffeine dose a dog took from chocolate in mg per kg of body weight, against the thresholds published in the Merck Veterinary Manual.

Cylinder volume from diameter and height, plus the contents of a part-full tank standing upright or lying on its side, in litres and gallons.

Combines the GPA and credits already on your transcript with a new term of courses, and finds the GPA a term needs to reach a target overall.

Turns an area and depth into tons of crushed stone to order, with coverage per ton, truck loads and cost, or works out how far a delivered tonnage spreads.

Shows the utilization ratio on each credit card and across all of them together, plus how much to pay down to reach a target percentage.

Estimates creatinine clearance with the Cockcroft-Gault equation from age, sex, weight and serum creatinine, reported in mL/min rather than as an eGFR.

Work out advertising cost per mille from spend and impressions, or go the other way to find the cost or the impressions a CPM rate buys.

Finds the balance you would need invested today to reach a retirement target on growth alone, with no further contributions, and compares it to what you hold.

Birth date to Chinese zodiac animal, element, yin or yang and the full sexagenary year pillar, using the real Chinese New Year boundary.

Runs a Pearson chi-square test, either goodness of fit against expected counts or a contingency table, and reports the statistic, degrees of freedom and p value.

Net operating income divided by property value, with vacancy and itemised operating expenses, plus the value a target cap rate supports.

Estimates the calories burned on a bike ride from weight, time and speed, and reports the total along with calories per hour and per mile.

Binomial probabilities for n trials at probability p: exactly k, at most k, at least k or a range between two counts, with the mean, variance and coefficient.

Build a bathroom renovation budget line by line: demolition, tub, vanity, toilet, tile, lighting, paint, plumbing and permit, with a contingency.

Checks your waist-to-height ratio against the Army standard of under 0.55, the only body composition measure since Army Directive 2026-13 rescinded the tape test.

Area of a rectangle, triangle, circle, trapezoid, parallelogram, ellipse or regular polygon, in the unit you enter and converted to square meters and feet.

Find how much water a rectangular, bowfront or cylinder fish tank really holds, after the glass thickness, the fill line and the substrate are taken out.

Estimate an AP score from a practice test for fifteen exams, each carrying its own published section weights, and see the composite behind the 1 to 5.

Estimate an ACT composite from raw section scores using a stated linear rule, or turn four scaled section scores into the exact composite.

Project a 401(k) balance from the percentage of pay you defer plus your employer match, and see how much match you leave behind by contributing less.

Turns a raw value, mean and standard deviation into a z-score, or a z-score into its percentile, normal-curve area and two-tailed p-value.

Estimates VO2 max from four field tests: a Cooper 12 minute run, a timed 1.5 mile run, the Rockport 1 mile walk, or your maximum and resting heart rates.

Works out the sidereal Lagna, the Moon's rashi and nakshatra, the Sun's rashi and the tithi from a birth date, time and place. An approximation, for fun.

Monthly payment on a used car once sales tax, dealer fees, a down payment and a trade-in are folded in, plus a side-by-side of 36 to 72 month terms.

Adds fuel, tolls, lodging and food into one road trip budget, splits it per traveller, and compares the cost of driving against flying.

Present value and future value of a single sum or of a level annuity, at any rate, term and number of periods per year.

Works out riser height, total run, diagonal stringer length, stair angle and throat depth in inches for a cut stringer hung off a deck or landing.

Reduces a square root, cube root or higher root of a whole number to simplest radical form and shows the factor pulled out plus the decimal value.

Combines like terms and expands brackets in a single-variable algebraic expression, and reduces a fraction to its lowest terms.

Estimates digital SAT section and total scores from the number of questions answered correctly, using a stated linear rule rather than an official curve.

Solves a right triangle from two legs, a leg and the hypotenuse, or a leg and an acute angle, returning every side, both angles, area and perimeter.

Compares renting with buying over the years you would actually stay, counting mortgage, tax, upkeep, closing and selling costs against rent and invested cash.

Turns body weight and a training goal into a daily protein target in grams, or converts a calorie total and protein percentage into grams.

Splits a month of rent for a move-in or move-out partway through it, using the days in that month, a flat 30 day month or a yearly rate.

Find the chance of a single event, combine two independent events with and, or and neither, or work out the odds across repeated tries.

Counts forward from your last period or a known ovulation date to the earliest date a home pregnancy test could give a reliable result.

Splits a proper rational function into partial fractions for two or three distinct linear factors, or a repeated linear factor beside a distinct one.

Works out the expression, soul urge and personality numbers from a name, and the personal year number from a birth date. Entertainment only, with no science behind it.

Work out miles per gallon from a tank of fuel, either from the miles you drove or from two odometer readings, with metric equivalents.

Multiplies two square matrices of the same size, 2x2 or 3x3, and shows the row-by-column sum behind every entry of the product so the working is visible.

Adds, subtracts and multiplies 2x2 and 3x3 matrices and finds the determinant, with rows typed as plain numbers separated by commas and semicolons.

Works out the logarithm of a number in any base, with the natural, common and binary logs alongside it, plus an antilog mode that inverts the result.