Online Calculators & Tools

Estimates an AP Seminar score from its three weighted parts: the team project at 20%, the individual research-based essay at 35% and the end-of-course exam at 45%.

Turns airflow and room size into air changes per hour, or a target rate into the CFM it needs, and reads a blower door test as ACH50 and a natural rate.

Works the air an engine needs in lb/min and the pressure ratio across the compressor, which together are the point you plot on a compressor map.

Surface area of a cube, box, sphere, cylinder, cone or square pyramid, split into the lateral area and the bases, in square metres, feet and inches.

Solves a two-variable linear system by substitution and writes out every step: the variable isolated, the expression substituted, the collecting, and the check.

Turns a screen diagonal and aspect ratio into width and height, works the throw distance from the projector's throw ratio, and places the seats.

Works out simple and discounted payback from a cash flow series, interpolating the part year, with the running balance for every period and a verdict against your cutoff.

Works out smoking pack-years from cigarettes or packs a day and the years smoked, and adds up several periods at different rates into one total.

Work out the MCA and the maximum overcurrent protection for air conditioning equipment from the motor currents, using NEC Article 440.

Work out enchanting table levels for any bookshelf count, anvil costs with the prior work penalty, and the experience between two levels in Java Edition.

Convert military time to the 12 hour clock and back, with the 0000, 2400 and 1200 midnight and noon cases handled, plus elapsed time past midnight.

Runs the Mann-Whitney U test on two samples, with the exact null distribution for small samples and a tie-corrected normal approximation for large ones.

Work out the Vimshottari mahadasha sequence from the Moon nakshatra, with the balance at birth, all nine periods and the antardashas. For entertainment.

Add up order lead time stage by stage, then work out the reorder point and safety stock from demand and lead time variability at a chosen service level.

Find the numerology karmic debt numbers 13, 14, 16 and 19 in a birth date or a name, with every step of the reduction shown. For entertainment.

Estimate how many days a flight will take to shake off from the time shift and its direction, and get a day by day light exposure schedule.

Differentiates a polynomial equation in x and y implicitly, giving dy/dx as an exact quotient, the second derivative, and the tangent line at a point.

Solve PV = nRT for pressure, volume, moles or temperature in your own units, run the combined gas law between two states, and get gas density from a molar mass.

Works out engine horsepower from torque and RPM through the 5252 relation, turns power back into torque, and converts a wheel figure into a crank figure.

Adds radon, sewer scope, termite, mould and re-inspection fees to the quoted base inspection, and shows how far the real bill sits above the headline number.

Turns seven heptathlon marks into IAAF points using the published scoring formulas, with the points for each event and the mark a points target needs.

Prices a gutter installation from your own per-foot rate, tear-off, guards, downspouts and corners, and turns a house footprint into linear feet and hangers.

Turns a CGM mean glucose into a Glucose Management Indicator and sets it beside a laboratory A1C, so the gap between the two becomes the number you read.

Adds a garage door replacement up from the door, hardware, labour, removal and permit you were quoted, and weighs repairing the old door against replacing it.

Fragrance oil weight for a given weight of candle wax at any load percentage, the same sum backwards, and the wax and oil a whole batch of containers needs.

Turn a fraction or a mixed number into a percentage, with the exact value when the division repeats, the lowest terms and the decimal alongside.

Convert a field of view between horizontal, vertical and diagonal at any aspect ratio, and carry a game FOV setting from a 4:3 or 16:9 base to your own screen.

Turn a target pounds of nitrogen per 1,000 square feet into pounds of an N-P-K product and bags to buy, or run it backwards from the bag you already have.

Name the face shape four measurements fall into, from forehead, cheekbone and jaw width and face length, with the rule that decided it printed alongside.

Transposes a prescription between plus and minus cylinder, reads out both eyes with the near power and spherical equivalent, and adds two lenses at different axes.

Crosses linear supply and demand curves to find the market price and quantity, with consumer and producer surplus and the effect of a tax or a price control.

Finds the empirical formula from a percent composition or a set of masses, shows every mole step, and gives the molecular formula when you add a molar mass.

The exact parts of an E6B: the wind triangle both ways, true airspeed and density altitude from the standard atmosphere, and leg time, fuel and reserves.

Work out how long a drive really takes: cruising speed, a traffic allowance, rest breaks, fuel stops, and the clock time you arrive across a time zone.

Dot product of two vectors in 2D or 3D, with both magnitudes, the angle between them, the projection of one onto the other and an orthogonality check.

Gallons of deck stain from the floor area plus the real surface of the railing, balusters and posts, at coverage rates for smooth or rough wood and for each coat.

Works out the challenge rating of a home-made D&D 5e monster from its hit points, armour class, damage per round and attack bonus, by the 2014 DMG table.

Critical values for the z, t, chi-square and F distributions at any alpha, one tailed or two, with the rejection rule and the confidence level spelled out.

Glucocorticoid equivalency reference: equal anti-inflammatory doses of prednisone, methylprednisolone, dexamethasone, hydrocortisone and the rest, side by side.

Estimates corn yield in bushels per acre by the yield component method, from an ear count in a measured length of row, kernels per ear and the kernel size factor.

Works out a year of credit card cash back from your own category rates and caps, compares a fee card against a no-fee one, and spreads a sign-up bonus over year one.

NEC 314.16 box fill: conductor, clamp, device, fitting and grounding allowances by wire size, against the cubic inches of a standard or marked box.

Places one systolic and diastolic reading in its 2017 ACC/AHA category, applying the higher-category rule, and gives the pulse pressure and mean arterial pressure.

Adds up the fourteen Berg Balance Scale items out of 56 and places the total in its published fall-risk band, with the tasks losing the most points named.

Estimates installed baseboard cost from room perimeters less door openings, with a mitre allowance, waste, whole sticks, labour, removal and painting.

Averages a set of blood pressure readings and gives the ACC/AHA category of the average, the spread, and the gap between the first reading and the rest.

Reduces an augmented matrix to reduced row echelon form and reports both ranks, whether the system is consistent, and the full solution set.

Net free ventilating area for an attic under the 1/150 and 1/300 rules, split between soffit intake and ridge exhaust and turned into a vent count.