Online Calculators & Tools

Orders a mixed list of integers, decimals, fractions, mixed numbers, percentages, square roots and multiples of pi, showing each one converted.

Finds k in y = k/x from a table of pairs, fills the gaps, and says whether the numbers really are an inverse variation at all.

Arcsec, arccsc and arccot of a value in degrees, radians, gradians and DMS, with the principal range and both arccot conventions.

Works out the gross bonus or relocation payment needed to leave an exact net, by the flat supplemental rate or by walking the tax brackets.

Read your four GED subject scores against the 145, 165 and 175 marks, see which subjects pass, and work out exactly what is still needed in each one.

Builds the full gear inch chart for a bike: every chainring against every cog, with the range, the duplicate gears and the size of each shift.

Works out g-force four ways: stopping or launching over a distance, a banked turn, a spin in revolutions per minute, and an impact after a fall.

Estimate free and bioavailable testosterone from total testosterone, SHBG and albumin using the Vermeulen equation, with both fractions and the constants shown.

Price a foundation repair from the pier count your wall needs and the rates you were quoted, with crack, bracing and drainage work costed separately.

Expected value, variance and standard deviation from a list of outcomes and probabilities, with the working shown outcome by outcome and the probabilities checked against one.

Decides whether two algebraic expressions are the same by expanding both to an exact canonical form, with the difference and a counterexample.

Dilates a point or a figure about any centre, giving the image coordinates, the coordinate rule and the length, perimeter and area factors.

Simplify (f(x+h) - f(x))/h for a polynomial, exactly, and see the limit as h approaches zero. Also evaluates the quotient at a chosen x and step size.

Exact odds for any dice roll: the chance of a total, of keeping the highest or lowest dice, and of rolling with advantage or disadvantage.

Turns a calendar date into its day number within the year, and a day number back into a date, with the days remaining, the quarter and the ISO week.

Predicts puppy coat colours from six dog coat loci at once, handling the way recessive red, dominant black and merle hide everything underneath them.

Works out a name number on the Chaldean chart, where letters run 1 to 8 and no letter is ever a 9, and reads the two digit compound number as well as the root.

Estimates the extra daily energy breastfeeding costs, from the baby's age and how much of the feeding is breast milk, or from a milk volume you have measured.

Works out the ankle-brachial index for each leg from four ankle pressures and two arm pressures, with the published bands and the calcified-vessel caveat.

Builds a trip budget from daily spending, nights, flights and a contingency, and reports the cost per person per day as the headline figure.

Works out a USSSA playing age from a date of birth and the program's determination date, then names the age group the player belongs in.

Turns two quantities into a unit rate and its reciprocal, and ranks up to four pack sizes at once to show which one is cheapest per unit.

Works out GD&T true position as twice the radial deviation from the basic location, with the bonus tolerance a circle M or circle L modifier earns.

Scales a standing tree into board feet from its diameter, merchantable height and form class, then prices it on Doyle, Scribner or International.

Adds static lift, pipe friction, pressure head and velocity head into the total dynamic head a pump has to deliver at your design flow.

Turns a daily step count into a calorie deficit and a range of likely weight change, showing both the 3,500 rule figure and the smaller one that allows for adaptation.

Sizes a solar battery bank from daily energy use, days of autonomy and depth of discharge, and compares lead acid against lithium on usable capacity.

Prices a septic system line by line: tank, excavation, drainfield, perc test, design, permits and restoration, with every rate an input you can overtype.

Turns a Galloway run-walk ratio and its two paces into one overall pace and a finish time, and solves backwards for the running pace a target needs.

Works out how much renters insurance cover you need: contents from a room-by-room inventory, replacement cost against actual cash value, liability and the deductible.

Clears a square root out of a denominator, either a single surd or a sum handled with its conjugate, with every step shown and the surviving root simplified.

Fills in the missing cells of a ratio table, shows the scale factor behind each column, and checks that the columns you already had agree with each other.

Works out the urine protein-to-creatinine ratio in mg/mg, mg/g and mg/mmol, grades it against the KDIGO bands and estimates the 24-hour protein.

Prices a pressure washing job surface by surface at its own rate, adds the trip charge, chemicals and minimum, and gives the blended cost per square foot.

Works out Fajr, Dhuhr, Asr, Maghrib and Isha from coordinates and a date, using the calculation method and Asr shadow rule you pick.

Finds the orthocenter of a triangle from three vertices as an exact fraction, with the altitude equations, the circumcenter, the centroid and the Euler line.

Reduces two birth dates to their life path numbers and scores the pairing from a fixed numerology scheme, with both of its tables shown. Entertainment only.

Adult maintenance IV fluid volume by the Holliday-Segar rule, showing both the 4-2-1 hourly rate and the 100-50-20 daily volume it was rounded from.

Bushels in a round grain bin from its diameter and grain depth, with the heaped cone, the hopper bottom, packing, test weight and drying shrink.

Works out gear ratio from tooth counts: a one, two or three stage gear train with output speed and torque, or a final drive from ring and pinion.

Sizes a garage heater in BTU and kW from the dimensions, the insulation, the overhead door and the slab edge, and prices four fuels against each other.

Raises a number or a fraction to a fractional exponent and returns the radical form, the exact simplified surd where one exists, and the decimal.

Builds the stainable surface of a fence board by board, both faces, picket edges, rails and posts, then prices the stain, prep, labour and tax from your rates.

Lays out a suspended ceiling grid: equal border cuts on facing walls, main runners at 4 ft, cross tees, panels whole and cut, and wall angle.

Prices a deck staining job: stain in the cheapest mix of quarts, cans and pails, plus cleaner, sundries, cost per square foot and cost per year.

Classic and skate ski lengths with pole lengths from your height and weight, using the published rules, and the weight chart set beside the height rule.

Counts a filing deadline in calendar or court days, rolls it off weekends and federal holidays, and adds the three days for service by mail.

Works out compa-ratio and range penetration from a salary and its pay band, shows which quartile the salary sits in, and what a raise does to both numbers.