Online Calculators & Tools

Works out a vertical jump from hang time or from standing reach and touch height, then estimates jump power with the named Sayers and Lewis formulas.

Prices a metered utility bill on tiered block rates, separating the fixed charges so the true marginal cost of the next kWh, therm or gallon is visible.

Volume of a pyramid with a triangular base, from the base and height of that triangle, its three sides, an equilateral side or a regular tetrahedron edge.

The vibrating string equation solved three ways: tension from pitch, pitch from tension, and both from a wire's material and diameter.

Tests whether a gap between two conversion rates is real. Gives the z score, the p value, a confidence interval on the difference, and the sample size a test needs.

Draws your paired data as a scatter plot with the least squares line on it, and gives r, r squared and the residual left at every single point.

Compares keeping a house as a rental against selling now and investing the proceeds, over the years you would hold it, with the cost of being a landlord included.

Splits rent between housemates by room size, by income or by the nights each person is there, with names kept and the odd cent given to somebody.

Works out the diluent to add to a powdered vial for a concentration you want, and the volume that carries a stated amount once it is mixed.

Gallons or litres a roof will collect from its footprint, the rainfall and a collection efficiency, plus the tank volume a dry spell of a given length needs.

Plans the quilt top: block count and cut size with seam allowance, sashing and cornerstones, border strips, and the yardage each colour needs.

Molecular weight of a protein from its one-letter amino acid sequence, with the monoisotopic mass, molecular formula, extinction coefficient at 280 nm and theoretical pI.

Concrete and bag counts for fence or deck post holes, with the post and the gravel base taken out of the volume instead of paid for.

Counts what a set of attacking types hits for super effective damage across the 18 pure types and all 153 dual typings, and ranks the combinations that cover most.

Weight of pipe per foot and for the whole run, from a nominal size and schedule, from a copper tube type, or from an outside diameter and wall you measured.

Percent yield from the actual and theoretical yield, and the theoretical yield itself from the limiting reagent, its molar mass and the balanced equation.

Builds the installed cost of a paver patio line by line, from pavers and base to labour, demolition, haul away, tax and contingency, and weighs a quote against laying it yourself.

Divides PaO2 by FiO2, takes mmHg or kPa and per cent or fraction, applies the altitude correction and reads off the Berlin severity band for ARDS.

Prices a seller financed note from the seller's side: the monthly payment, the balloon, the interest you earn on it, and what a note investor would pay for it.

Writes the molecular, total ionic and net ionic equation for a precipitation or neutralisation reaction, names the spectator ions and gives the solubility rule used.

Works out a player's Little League age for baseball or softball from a date of birth, and lists the divisions that league age is eligible for.

Prices a mowing visit from the grass that is actually cut, taking the house and the driveway off the lot, then adds trimming, edging and the cleanups for a whole season.

Works out the Kelly stake from the odds on offer and the probability you think is right, in decimal, American or fractional form, with fractional Kelly and the growth rate.

Adds up an HVAC replacement from your own quoted rates: equipment, labour hours, duct work, line set, permit, removal, tax and rebates, with the cost per ton.

Prices a cleaning visit by floor area, by room count or by the hour, with the depth of clean, the recurring discount and every rate left as an input.

Sets a horse's daily forage and concentrate as a percentage of bodyweight for its workload, checks it against the published NRC ranges and plans a gradual change.

The great-circle midpoint between two latitude and longitude pairs, with the distance, the bearing from each end, and the point at any fraction of the route.

Morning and evening golden hour, blue hour and the three twilights for any date and place, worked out from the sun's altitude rather than a rule of thumb.

Sizes a gas strut for a hinged lid or hatch from the moment balance about the hinge, giving the force per strut and the moment arm through the whole swing.

Turns hours worked into full-time equivalents at your own full-time week, converts a headcount to total FTE, and applies the ACA 30-hour rule separately.

Prices up to three flooring materials side by side for the same room, comparing installed cost, cost per square foot, cost per year and cost over the years you will keep it.

Equipment loan payments, and a loan set against a $1 buyout lease and a fair market value lease after tax, with the interest rate a lease quote never shows you.

Multiplies mouse DPI by in-game sensitivity to give eDPI, converts it to centimetres per 360 at a stated game yaw, and matches a sensitivity between two games.

Works out the milligrams of THC in each piece of an edible, from the flower or concentrate that went into a batch or from the total printed on a package.

Finds the diagonal of a rectangle or a box, turns a screen diagonal and an aspect ratio back into a width and a height, and counts the diagonals of a polygon.

Compares two or more fractions by cross-multiplication with the working shown, puts them in order, and rewrites every one over their lowest common denominator.

Elo expected score, rating change after a game or an event at any K factor, and the performance rating a tournament score works out to.

Prices a cake from ingredients, hours at your own rate, overhead and margin, and works out how many servings a round, square or tiered pan actually cuts.

Sizes a bridge loan against the equity in the home you are selling, then shows the interest-only payment, the balloon, the fees and the cost of carrying both homes.

Break-even units and revenue from fixed costs, price and variable cost, with the contribution margin, the margin of safety and the volume a target profit needs.

Which ABO and Rh blood types a child can have, from the parents' types, plus exact Mendelian percentages when the parents' genotypes are known.

Average atomic mass from up to six isotope masses and their natural abundances, with each isotope's contribution shown and the abundances held to a total of 100 percent.

Reads a dimension off a drawing at an architect's or engineer's scale, gives the size to draw in inch fractions, and picks the largest scale that fits the sheet.

Estimates how long until blood alcohol returns to zero after drinking, from drinks, body weight and time elapsed, with the range around that estimate.

Work out how many lands a Magic deck needs. Hypergeometric odds for the opening hand, for hitting every land drop through a given turn, and after a London mulligan.

Seed for a new lawn or an overseeding, from the area and the grass, with the published rate per species editable and the starter fertiliser alongside.

Run both phases of a deferred annuity: what a premium and its contributions grow to, and the fixed-term income that pot then buys.

Planetary lines on a world map from a birth moment: the MC and IC meridians, the rising and setting curves, and which of them pass near a place you name.