Online Calculators & Tools

Offset, three point saddle and stub up marks for conduit, with the bender multipliers and the shrink that has to be added before you mark.

Work out the early withdrawal penalty on a CD, what you actually walk away with, and the month at which cashing it in stops eating part of your deposit.

Tubes of caulk from the width, depth and length of the joint, with the sealant depth and the backer rod size that joint should have.

Score a whitetail rack on the Boone and Crockett chart, typical or non-typical, with every right-to-left deduction shown line by line.

Exact two-pulley belt length from both diameters and the centre distance, with wrap angles, straight spans and a scale drawing, plus the centre distance for a belt you already own.

Work out the magic number for the team in front, the elimination number for the team behind, and the division magic number against every rival at once.

Bat length as a range from both the age chart and the height chart, plus the drop, the ounce range and the certification your league requires.

Score the ten activities of daily living on the Barthel Index, from feeding to stairs, and get the total out of 100 with the dependence band it falls in.

Work out acres covered per hour from implement width, ground speed and field efficiency, then turn it around for the hours a field takes or the width a deadline needs.

Astable frequency, period and duty cycle from R1, R2 and C, monostable pulse width from R and C, and the reverse solve with nearest E12 and E24 values.

Balanced three-phase power from the impedance of one winding, in wye or delta, keeping line and phase voltage and current apart and showing where the 1.732 factor belongs.

Converts watt hours to milliamp hours at a voltage you supply, and restates a mAh rating at a different voltage with converter losses allowed for.

Works out the water standing in a cased well from the casing bore, the total depth and the static water level, with gallons per foot and the purge volume.

Project a Thrift Savings Plan balance with the real agency contribution: the automatic 1%, the two-step match, and what front-loading the limit costs you.

Thrift Savings Plan loan payments at the G Fund rate, the three tests that set the maximum you may borrow, and what the loan really costs your account.

Type a balanced equation and the amount of one species, and get every other species in moles and grams, with the mole ratio and the limiting reagent.

Baker's percentage for sourdough bread, with the levain's own flour and water taken out of the weigh-out, plus bulk timing and water temperature.

Score a reading running record: accuracy rate, error rate as a 1:N ratio, self-correction rate and the independent, instructional or frustration band.

Find the root mean square of a list of numbers, or convert between the RMS, peak, peak-to-peak and average values of a sine, square, triangle or rectified waveform.

Work out the required minimum distribution from a traditional IRA or workplace plan using the IRS Uniform Lifetime Table, and project the distributions forward.

Left, right, midpoint and trapezoidal sums for one integrand at once, with the strips drawn, the exact value from the antiderivative and each rule's error.

Decide whether a number is rational or irrational, with the exact fraction when it is one and the named theorem when it is not.

Work out the range, maximum height, flight time and trajectory of a projectile, with or without a launch height, and find the angle or speed that hits a target.

PCR primer Tm by nearest-neighbour thermodynamics, with the 2 + 4 Wallace rule and the GC formula printed beside it so the gap between them is visible.

Find the sample size a study needs, or the power it already has, for comparing two means or two proportions, using the noncentral t distribution rather than a shortcut.

Price a plumbing job from the fixture count, separate rough-in and finish rates, pipe runs, permits and markup, or work out what a single service call should come to.

Solves Darcy-Weisbach backwards: the water flow a pipe passes for the pressure you have, or the bore a target flow needs inside a loss budget.

Find the outliers in a list by the IQR fence rule, the z-score, the modified z-score on the MAD and Grubbs' test, and see where the four disagree.

Old School RuneScape combat level from your seven stats, with the working shown and the exact levels needed to reach the next combat level.

Odds ratio from a 2 x 2 table with the log-scale confidence interval, the Haldane correction for an empty cell, and the relative risk printed beside it.

Occupant load from floor area using IBC 2021 Table 1004.5 factors, with the exits, egress width and corridor width that load requires.

Simulates thousands of retirement drawdowns with volatile returns and reports the whole percentile band, not just a success rate. Same inputs, same answer.

Finds the cost of one more unit, from two production levels or from a cost curve, and shows where marginal cost crosses average cost.

Differentiates log_b(u(x)) by the chain rule, and does logarithmic differentiation of a product, a quotient or a variable exponent.

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.