Online Calculators & Tools

Works out a mod n, adds, multiplies and raises to a power inside a modulus, and solves a x = b (mod n) to find modular inverses.

Converts Overworld coordinates to Nether coordinates and back at the fixed 1:8 ratio, and checks whether two portals will end up sharing a link.

Panel take-off for a metal roof: how many panels of a given coverage width, how long, how many seams, and what they cost at your price per linear foot.

Sodium or potassium hydroxide and water for a soap batch, from your oil weights, their saponification values and the superfat you choose.

Recalculates undergraduate grades the way LSAC summarizes them: an A+ worth 4.33, every repeated attempt counted, and penalty withdrawals counted as zeros.

Punnett square for a foal's colour across five tested loci: extension, agouti, cream, dun and grey, with the chance of each colour and the genotypes behind it.

Bands your height and wrist-to-floor measurement on the standard static fitting chart and lays the length adjustment over a full set of clubs.

Profit and loss on a futures position from the contract multiplier or the tick value, with commission, notional value, leverage and return on margin.

Puts numbers in place of the letters in an algebraic expression and works out the result, showing the substitution and one operation per step.

Reduces a fraction to lowest terms and lists fractions equal to it, checks whether two fractions match, and fills the gap in a statement like 3/4 = ?/20.

Works out a dwelling's calculated load in volt-amperes by the NEC Article 220 standard method or the 220.82 optional method, from nameplate ratings you enter.

Checks whether one whole number divides another, shows the remainder and names the divisibility rule, or tests a number against every divisor from 2 to 100.

Builds a matrix of destiny chart from a birth date: the four square points, the four diagonals, the centre and the purpose ladder, with the working shown.

Solves ax^3 + bx^2 + cx + d = 0 by Cardano's method and returns all three roots, including complex ones, with the discriminant.

Add, subtract, multiply and divide complex numbers, convert between a + bi and polar form, and take integer powers and all nth roots by De Moivre.

Rewrites a quadratic as a squared bracket plus a constant and shows every step, then solves it by taking a square root instead of quoting the formula.

Builds a vinyl wrap estimate from film, waste, fitting hours and extras at your own prices, or breaks a quote you already have into film and labour.

Scores a ten-pin game frame by frame from the rolls you write down, showing how each strike and spare carries into the frames after it.

Splits your weight into fat and lean mass and moves them in opposite directions, so a recomposition shows up where the scale hides it.

Compares an accelerated biweekly schedule with monthly payments on the same loan: the payoff date, the time cut off the term and the interest saved.

All four BaZi pillars from birth details: year, month, day and hour, with the year turning at Lichun and the months set by the sun's ecliptic longitude.

Works out an aircraft loan payment, including the balloon these notes often carry, then adds hangar, insurance and fuel to give a cost per flight hour.

What a print costs to run: filament or resin, electricity, printer depreciation, your time and a failure allowance, plus a price at the markup you set.

The smallest copper conductor that carries the load and holds voltage drop, from NEC Table 310.16 with ambient, conduit fill and continuous load applied.

Rolls of wallpaper for a room, worked out from the wall run, the ceiling height, the pattern repeat and the width and length of the roll.

Work out your VDOT from one race result, see the equivalent times at nine other distances, and turn it into the Daniels E, M, T, I and R training paces.

Works the t statistic out from sample means, standard deviations and sizes, one sample or two, and gives the degrees of freedom, the p-value and the critical t.

Recommended surfboard volume in litres from your body weight, ability and the waves you surf, using the published Guild Factor shortboard bands.

Counts the time since a date you enter: days, weeks, whole months, a years-months-days breakdown, and the dates the usual day and year marks fall on.

Works out siding in squares and boxes from wall area less doors and windows, with a waste allowance, and totals the cost at your own prices.

Calculates serum osmolality from sodium, glucose and urea in US or SI units, and returns the osmolal gap when you add a measured osmometer result.

Return on a rental across the whole time you hold it, with the profit split into cash flow, appreciation, principal paid down and the costs of the deal.

Totals the calories, protein, carbohydrate and fat of a recipe from figures you take off the labels, then divides them per serving and per 100 grams.

Usable capacity, parity overhead and fault tolerance for RAID 0, 1, 5, 6 and 10, from the number of drives and the size of one drive.

Converts a gestational age in weeks and days into months, both ways, and states the rule it uses instead of leaving you to guess which chart is right.

Identifies a conic section from its general equation and returns the standard form, centre, vertices, foci, eccentricity, asymptotes and directrix.

Monthly payment on a swimming pool loan with the pool's running cost carried alongside it, or the project a monthly budget supports once upkeep is taken out.

Evaluates a piecewise function you enter as numbered pieces with numeric bounds, at one value of x or across a range, and says which piece was used.

Turns a t statistic or an F statistic and its degrees of freedom into a p-value, in either tail, with the tail computed rather than read from a printed table.

Net present value of a series of cash flows at a discount rate you choose, with the present value of each period, the profitability index and discounted payback.

Compares the lump sum against the annuity on a lottery jackpot: cash option, the graduated payment schedule, tax at a rate you enter and the break-even return.

Works out LTV, CLTV and HCLTV from a property value and the liens against it, and what it takes to bring a balance down to a target ratio.

Kinetic energy from mass and velocity, or the formula rearranged to recover the mass or the speed. Metric and imperial units throughout.

Inverts eleven standard Laplace pairs, and proper fractions over two or three different real linear factors, returning the residues, f(t) and a value at t.

Budget frame for renovating a whole house: general work by the square foot, plus wiring, plumbing, heating, windows, roof, kitchen and bathrooms as their own lines.

How hot the air actually feels once humidity is counted, from the published National Weather Service Rothfusz regression and its corrections.

Graphs a linear inequality in two variables as a shaded half-plane, with a solid or dashed boundary, a test point and the region of a system.

Score differential, handicap index average and course handicap, worked the World Handicap System way from your scorecard numbers.