Online Calculators & Tools

Draws a box and whisker plot from your data, with the five number summary, the IQR, the Tukey fences and every outlier named.

Averages a list of durations, and averages times of day with the circular mean, so 23:00 and 01:00 come out as midnight rather than as noon.

Averages percentages the right way. Enter each percentage with the group size behind it and see the weighted answer next to the plain mean of the percentages.

One-way analysis of variance for up to six groups. Returns the sums of squares, degrees of freedom, mean squares, the F statistic and an exact p value.

Turns an oven temperature and time into air fryer settings, 25 degrees lower and a fifth less time, and gives the safe internal temperatures that actually decide doneness.

Works out the acreage of a lot from its length and width, its three sides, or its corner coordinates, and converts between acres, hectares, chains and rods.

Paste a run of annual figures and get the growth from each year to the next, the total change and the compound annual rate that connects the ends.

Converts a lens power between two vertex distances, such as a spectacle prescription to the corneal plane, meridian by meridian.

Solves ax + b = c, x/a + b = c and equations with x on both sides, writing out every step with both sides shown and the answer substituted back as a check.

Evaluate a triple integral over a rectangular box, a cylindrical wedge or a spherical shell, with the inner integrals shown and a numerical check alongside.

Works out time-lapse settings in either direction: clip length, card space and batteries from an interval, or the interval that fits an event into the clip you want.

Weighs a student loan refinance rate saving against what it ends: income-driven repayment, PSLF credit and the balance that would have been forgiven.

Works out the new average cost per share after you buy more of a holding, with the break-even price and the gain it would take to get back there.

Lambing date from the breeding date on a 147 day gestation, the service date for a wanted lambing date, and the lambing period from a ram in and ram out date.

Converts between real sizes and scale sizes for models and maps, finds the ratio behind two measurements, and re-scales a size from one ratio to another.

Block, cap, levelling pad and drainage stone for a segmental retaining wall, from wall length, exposed height and the block size you are using.

Solve an equation with x in the denominator, clearing the fractions and then throwing out the extraneous roots that a plain equation solver would keep.

Strips and yardage for binding a quilt, counting the length every diagonal join eats, with straight-grain and continuous-bias cutting.

Works out the days supply from the quantity and the dose, the date the supply runs out, and the earliest date a pharmacy will usually refill it.

Plot a polar curve on a polar grid with a table of theta, r, x and y, plus the petal count, the maximum radius, the symmetry tests and the area swept.

Finds the payment at which a loan reaches 80% and 78% of its original value, the midpoint termination date, and what extra principal moves.

Scales pizza dough by baker's percentage: flour, water, salt, oil and yeast from the number of balls, their weight and the hydration you want.

Trace width from current and temperature rise by the IPC-2221 conductor charts, with copper weight, cross-section, resistance, voltage drop and power.

Muzzle energy in foot-pounds and joules from bullet weight in grains and velocity in feet per second, with momentum, power factor and Taylor KO.

Price a temporary 2-1, 3-2-1 or 1-0 mortgage buydown: the escrow the seller funds, the payment in each bought-down year, and what it climbs back to.

Area moment of inertia for rectangles, tubes, pipes, I-beams and T-sections about both axes, with section modulus, radius of gyration and the parallel axis theorem.

Builds a mold remediation estimate line by line: area, containment, HEPA scrubbing, material removal, disposal and testing, each at a rate you supply.

Turns a framing order into pieces, linear feet and board feet, with nominal sizes converted to the actual dressed dimensions and a cut list from stock lengths.

Board feet in a log under the Doyle, Scribner and International 1/4-inch rules side by side, from small-end diameter and length, with a tally for a whole load.

Draw the K-map for 2, 3 or 4 variables from your minterms and don't cares, group it, and return the minimal sum of products and product of sums.

Converts an inequality to interval notation and back, handles and, or and unions, and works out the union, intersection or difference of two intervals.

Work out a mare's foaling date from the cover date on a 340 day gestation, with the normal day 320 to day 370 window and the usual scan and vaccination dates.

Works out HOMA-IR from a fasting glucose and a fasting insulin in either unit system, with HOMA-B and QUICKI from the same pair.

Convert a 4.0 GPA to a percentage on the scale you name, with all three common tables shown side by side and the gap between them spelled out.

Read a club's swing weight on the Lorythmic scale from its total weight and balance point, or from head, shaft and grip weights, and see what a weight change does.

Kidding date from the breeding date, or the service date for a kidding date you want, with a window and the usual dates around it.

Works out the LTL freight class from shipment density. Enter the crate dimensions, the piece count and the weight for cubic feet, lb per cubic foot and the class.

Measures a stack in full cords and face cords, converts a face cord quote to a real price per cord, and works out the heat the wood delivers.

Turns a cutting speed and a chip load into spindle RPM and feed rate for milling or turning, with radial chip thinning and the metal removal rate.

Encounter difficulty for D&D 5e from the 2014 DMG tables: party XP thresholds, the encounter multiplier for monster count, and the adventuring day budget.

Work out click-through rate from clicks and impressions, find the clicks a target CTR needs, and test whether two versions really differ.

Turns a length and a girth measurement into the nominal width printed on a condom box, plus the length range to look for and how the figure is worked out.

Price a concrete driveway as a full takeoff: thickness for the traffic, concrete to the quarter yard, gravel base in tons, mesh or rebar, and the control joint layout.

Work out what driving to work costs over a full year in fuel, wear and parking, and set that total against a transit pass or a carpool share.

Turn a neck, sleeve, chest or bust measurement into a shirt size, a jacket size and a letter size, with the UK and European numbers alongside.

Estimates a child's adult height from both parents using the mid-parental method, and gives the 10 cm range either side that the estimate is really good to.

Counts the parts a chain link fence takes and prices them: line and terminal posts, top rail, fabric rolls, tension bars, bands, caps, ties and concrete.

Set your monthly take-home pay against every expense category, see the surplus or shortfall, and compare the result with the 50/30/20 split.