Online Calculators & Tools

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.

Finds the sign and degree of mean Black Moon Lilith, the apogee of the Moon's orbit, from a birth date and time, with the ingress dates either side.

Splits a bill that does not divide evenly: each person pays for what they ordered with tax and tip shared in proportion, or the total is split by uneven shares.

Works out arrow FOC from a measured balance point or from the component weights, and gives the balance point, total arrow weight and grains per pound.

How much gravel, sand or planted substrate a tank needs, in pounds and kilograms, from the footprint, the depth and the bulk density of the material.

Apply a named, published spousal support guideline to two incomes and see every step of it, or run all five side by side to see how far apart they land.

Works out 0-60 acceleration three ways: average g and distance from a time, the time from a distance and a speed, and an estimate from weight and horsepower.

Works out which zodiac sign Venus was in from a birth date and time, with the exact degree, whether it was retrograde and how far it stood from the Sun.

Commercial truck finance with a balloon residual, terms out to 120 months, the payment expressed per mile, and the first year write-off on the purchase.

Solves any triangle from three measurements, SSS, SAS, ASA, AAS or SSA, returning every side, every angle, the area, the heights and both radii.

Approximates a definite integral with the trapezoidal rule, over a polynomial, a standard integrand or a table of measured points, with the error bound.

Adds up a tow the way the invoice does: hook-up fee, billable miles, after-hours and winch-out surcharges, storage and tax, from the rates you were quoted.

Gives the tangent line to a curve at a point, the normal line through the same point, and the linear approximation with the error it makes nearby.

Finds the rule behind a list of numbers, arithmetic, geometric, quadratic or Fibonacci style, then gives the nth term, the sum and the terms that come next.

Turns an efficiency rating into money: annual cooling cost at your own electricity rate, the saving from a higher rating, the payback on the price difference.

Works out engine RPM from road speed, tire size, gear ratio and final drive, and runs the same chain backwards for road speed or the axle ratio you need.

Works out the 500 m split, the finish time and the wattage for an erg piece, converting freely between any two of distance, time, split and power.

Estimates resting metabolic rate from lean body mass with the Katch-McArdle and Cunningham equations, so body composition drives the answer rather than height and age.

Turns a word count or a block of pasted text into a reading time at the speed you pick, and works backwards from a slot to the words that fit it.

Turns output and hours into productivity per hour and per worker-hour, measures how much of the available time was productive, and compares two periods.

Works out the pointwise mutual information of two events from their joint and marginal probabilities, or from raw counts and a corpus size, with PPMI and normalised PMI alongside.