Online Calculators & Tools

Finds the orthocenter of a triangle from three vertices as an exact fraction, with the altitude equations, the circumcenter, the centroid and the Euler line.

Reduces two birth dates to their life path numbers and scores the pairing from a fixed numerology scheme, with both of its tables shown. Entertainment only.

Adult maintenance IV fluid volume by the Holliday-Segar rule, showing both the 4-2-1 hourly rate and the 100-50-20 daily volume it was rounded from.

Bushels in a round grain bin from its diameter and grain depth, with the heaped cone, the hopper bottom, packing, test weight and drying shrink.

Works out gear ratio from tooth counts: a one, two or three stage gear train with output speed and torque, or a final drive from ring and pinion.

Sizes a garage heater in BTU and kW from the dimensions, the insulation, the overhead door and the slab edge, and prices four fuels against each other.

Raises a number or a fraction to a fractional exponent and returns the radical form, the exact simplified surd where one exists, and the decimal.

Builds the stainable surface of a fence board by board, both faces, picket edges, rails and posts, then prices the stain, prep, labour and tax from your rates.

Lays out a suspended ceiling grid: equal border cuts on facing walls, main runners at 4 ft, cross tees, panels whole and cut, and wall angle.

Prices a deck staining job: stain in the cheapest mix of quarts, cans and pails, plus cleaner, sundries, cost per square foot and cost per year.

Classic and skate ski lengths with pole lengths from your height and weight, using the published rules, and the weight chart set beside the height rule.

Counts a filing deadline in calendar or court days, rolls it off weekends and federal holidays, and adds the three days for service by mail.

Works out compa-ratio and range penetration from a salary and its pay band, shows which quartile the salary sits in, and what a raise does to both numbers.

Monthly cost of a commercial lease with CAM, tax and insurance pass-throughs, the load factor between rentable and usable space, and the effective rent.

Turns the parts of a Chapter 13 plan into a monthly payment, or a payment you can afford into the dividend unsecured creditors receive, with the trustee fee grossed up.

Theoretical boat speed from propeller pitch, engine rpm and gear ratio, propeller slip from a measured GPS speed, and the pitch change for the rated rpm range.

BMX roll-out, gain ratio and gear ratio from the sprockets, the real wheel and tyre, and the crank length, with two setups compared side by side.

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.