Online Calculators & Tools

Frame size bracket from inseam, plus the stack and reach trigonometry that says where a stem and spacer stack actually put the bars, and what matches one frame to another.

Sizes a bathroom exhaust fan by floor area, by air changes and by fixture count, then works out how much of that rating the duct run will actually let through.

Builds a collision estimate from body hours, refinish and blend panels, paint materials, parts and tax, then tests the total against the vehicle value.

Works out what an acceptance sampling plan actually does, computing the operating characteristic curve exactly from the hypergeometric distribution rather than reading a table.

Works out the water needed to bring a spirit down to a target ABV, including the contraction that makes ethanol and water mix to less than the sum of their volumes.

Air density from temperature, absolute pressure and humidity, treating dry air and water vapour as separate partial pressures, plus the standard atmosphere at any altitude.

Solves a bond's yield to maturity from its price, coupon, face value and term, with the current yield, the yield to call and the price-yield curve.

Exact sine, cosine and tangent anywhere on the unit circle, with the quadrant, the reference angle, the coterminal angle and the point written in radicals.

Prices a T-bill from its quoted discount rate and returns the discount rate, the money market yield and the Treasury investment rate side by side.

Pace from a treadmill belt speed, plus the incline adjustment: the flat belt speed and the outdoor pace that cost the same oxygen, from the ACSM equations.

Billable units from treatment minutes under the Medicare 8-minute rule, and the productivity percentage those units give against a worked day.

Turns text into binary, hexadecimal, decimal, octal and Base64 and back again, in UTF-8, with a table showing which bytes belong to which character.

Swingweight, balance and twistweight for a tennis, squash, padel or badminton racket, and exactly what a strip of lead tape at a chosen spot does to all three.

Margin per box from goods, packaging, shipping and payment fees, then churn-adjusted lifetime value against acquisition cost, which is the number that decides it.

Writes any number as a x 10^n, expands a standard form pair back into an ordinary number, and multiplies, divides, adds or subtracts two of them.

Splits a staircase across a landing: equal risers throughout, a separate stringer and run for each flight, the footprint, and the code limit on rise per flight.

Prices a spray foam job in board feet: area times depth, sets to order, cost per square foot, and open cell against closed cell for the same R-value.

Corrects serum sodium for hyperglycaemia by both the Katz 1.6 and the Hillier 2.4 factors, shows how far apart they are, and checks a rate of change.

Converts a slope between a percent grade, a 1-in-N ratio, an angle in degrees and a rise over a run, and checks it against the ADA and drainage limits.

Applies the ratio, root, integral, limit comparison and alternating series tests to a general term, with the limit, the verdict and the reason for each.

Prices a second home loan with its higher rate and down payment, prorates the mortgage interest deduction across the shared debt cap, and runs the rental-use test.

Finds the scale factor between two similar figures from matching sides, areas or volumes, and gives the area factor squared and the volume factor cubed.

Works out a couple's retirement number with the survivor case, two retirement dates and a horizon that runs to the second death rather than the first.

Works out how much of a radioisotope is left after a given time, the activity in becquerels or curies, the half-life from two readings, and a parent-daughter chain.

Sizes a pool pump properly: the flow your volume and turnover need, the total dynamic head the plumbing puts in the way, and what the power costs to run.

Counts the evolutions your candy allows, including the candy transferring gives back, the walking that closes a shortfall and what fits in a Lucky Egg.

Cuts real daylight and real night into twelve unequal hours each and names the Chaldean ruler of every one, from your coordinates and a UTC offset.

Works out what percent of a goal you have reached, and whether the pace is fast enough to finish by the deadline.

Exact Pot Limit Omaha equity for two to four hands from the flop, turn or river, plus a showdown reader that enforces the exactly two hole cards rule.

Estimates total-body skeletal muscle mass from Lee's MRI-validated anthropometric equations, with the skeletal muscle index and the real error band.

Works out the MELD 3.0 liver disease severity score, and the older MELD-Na, applying the published flooring, capping and dialysis rules to each lab value.

Post-judgment interest to any date, at the statutory rate you enter, simple or compounded, with partial payments applied to interest first.

Puts two heights side by side, gives the difference in feet, inches and centimetres, the ratio between them, and draws both to scale on one baseline.

Estimates GRE Verbal and Quantitative scores from a raw count using one stated linear rule, and works out what the second section has to reach a target.

Works out the glucose ketone index from a blood glucose and a blood ketone reading, converts mg/dL to mmol/L, and names the band the result falls in.

Turns a run of wall into a priced framing takeoff: studs, plates, headers, sheathing, fasteners and labour, with every rate an input rather than a guess.

Works out force five ways: Newton's second law, weight under any gravity, friction on a slope, centripetal force in a turn, and a spring under Hooke's law.

Works out what is genuinely left for an engagement ring after the wedding, the honeymoon, a deposit and everything else the same money owes. No suggested price.

Turnover rate from separations and average headcount, annualised, split into voluntary and involuntary, with a separate costing of what a replacement takes.

Kinematic displacement: how far an object ends up from where it started, from velocity and acceleration or from the legs of a journey, with the distance travelled beside it.

Scores a decathlon from the World Athletics tables: all ten marks, one event on its own, or the mark a points target needs.

Debt yield from net operating income and loan amount, sized against loan to value and debt service coverage so you can see which of the three tests binds.

Works out days payable outstanding from payables and cost of sales, then sets it beside days sales outstanding and days inventory in the cash conversion cycle.

Finds the weekday of any date by Zeller's congruence or the doomsday rule, handling the Julian to Gregorian switch that trips up most date tools.

Converts chmod permissions between octal and symbolic, builds a mode from tick boxes, and shows what each bit means on a directory as against a file.

Reactions, shear, bending moment and deflection for a simply supported span or a cantilever under a uniform load, a point load, or both.

Inverse tangent in degrees, radians and gradians, with the principal value, the full family of angles, and the two-argument atan2 form.

Typing speed in words per minute from a passage or a character count, with gross and net WPM, the error penalty, accuracy, CPM and keystrokes per hour.