Online Calculators & Tools

Crosswind and headwind components from a runway heading, the wind direction and speed, with a magnetic or true reference and an optional gust figure.

Turns a chart's stitch count into a finished size on Aida, evenweave or linen, and the piece of fabric you need to cut for it.

Concrete volume and the rebar schedule for pad and continuous footings: cubic yards, bags, linear feet of steel and its weight by bar size.

Exact arithmetic on whole numbers of hundreds of digits: add, subtract, multiply, divide with a remainder, raise to a power or take a factorial.

Models an adjustable-rate mortgage through its caps: the starting payment, the worst case at every reset and the highest payment the note allows.

Finds the angle whose cosine is the value you enter, in degrees and in radians, and refuses values outside the -1 to 1 domain with a reason.

Finds the indefinite integral of polynomial terms by the power rule, plus 1/x, e^x, sin, cos and sec squared, and refuses anything outside that list.

The exact gap between two birth dates in years, months and days, both ages on any date, the ratio between them and the day the gap was two to one.

Works out the absolute neutrophil count from the white cell count and the neutrophil percentages on a blood report, in both cells/uL and 10^9/L.

Daily water target from the published Adequate Intake table or from your body weight, in litres, US cups and fluid ounces, with an allowance for exercise.

Turns questions missed, or points earned out of points possible, into a percentage and a letter grade, and says what the next letter up would take.

Expands e^x, sin x, cos x, ln(1+x) or the geometric series into a Taylor polynomial about any centre, then checks that polynomial against the true value.

Evaluate sigma notation term by term, use the closed form for an arithmetic or geometric series, or simply add up a list of numbers you paste in.

Turns a lawn area into rolls and pallets of sod, with a waste allowance for curved edges and beds, and the cost by the roll against the cost by the pallet.

Counts one Saturn orbit forward from your birth date to date your first, second and third Saturn return, with the window around each one.

Measures what you have saved against the published savings factors for each age: 1x income by 30, 3x by 40, 6x by 50, 8x by 60 and 10x by 67.

Monthly cash flow, cash on cash return, cap rate and debt service coverage for a rental, with every expense line shown and the mortgage counted.

Splits a holding period return into price and income, averages a run of yearly returns the way they actually compounded, and strips out inflation, fees and tax.

Turns a total price and a floor area into a rate per square foot, metre, yard and acre, compares two properties, and prices a commercial lease per month.

Damage rolls for a Pokemon battle using the main-series formula from Generation V onward. Enter the level, base power, both stats and the modifiers that apply.

Odds of catching a Pokemon from the species catch rate, remaining HP, ball and status, using the published capture check for Generation V onward or for III and IV.

Works out how many pizzas of a given size feed a group, in square inches rather than guesswork, and compares two sizes for value.

Finds the percentile rank of a value in a data set, the value that sits at any percentile, and the quartiles with the interquartile range.

Estimates the fertile window from the shortest and longest cycles you actually have, or from your last few period dates. An estimate, not contraception.

Area under the normal curve between two x values, and the reverse: the value sitting at any cumulative probability, from a mean and a standard deviation.

Prices the dealer's two offers against each other: the promotional low APR on the full price, or the cash rebate financed at your own bank's rate.

Turns a paycheck and its pay schedule into gross monthly income, counting 26 fortnightly paydays a year, and adds up several income sources at once.

Adds up total daily morphine milligram equivalents using the conversion factors CDC published in 2022. It is not a way to convert one opioid into another.

Looks up what one published cohort found: how many pregnancies with a heartbeat seen at 6 to 10 weeks went on to miscarry. A record, not a prediction.

Finds the midpoint of two coordinate points, the missing endpoint when you know one end and the midpoint, and midpoints in three dimensions.

Mean, median, mode and range from one list of numbers, with the full five number summary, the interquartile range and any outliers.

Finds the mean absolute deviation of a list of numbers or a frequency table, about both the mean and the median, with every distance shown.

Finds the Maya day sign for a birth date from the 260 day Tzolkin count, with the Haab date, the Long Count and the correlation constant it used.

Totals linear feet for trim, fencing or gutter: around a room with the doorways taken out, from a list of measured pieces, or as whole boards to buy.

Applies the law of cosines on its own: a third side from two sides and the angle between them, or any angle from three sides, with every step shown.

A line by line kitchen remodel budget at three finish levels, with cabinets by the linear foot, counters by the square foot, and a list of what it leaves out.

Estimates a home addition line by line: new floor area, foundation, tie-in to the existing house, bathrooms, heating, design fees and contingency.

Scores an English word in six gematria ciphers at once, or a Hebrew word by its standard letter values, and shows the letter-by-letter sum.

Work out the oil for a two-stroke mix at any ratio, check the ratio you actually poured, or find the fuel that matches a bottle of oil you already have.

Great circle distance between two sets of coordinates and the flying time at a cruising speed you choose, plus a ground allowance and the initial heading.

Fat-free mass index from weight, height and body fat, with the height-normalized version, in metric or imperial units.

Work out engine displacement from bore, stroke and cylinder count, in cc, litres and cubic inches, with an optional overbore for a block bored oversize.

Counts the drywall sheets a room needs and prices the job from your own sheet cost and hanging rate, with openings deducted and a waste allowance added.

Dilutes a stock to a target strength in percent, mg/mL or ppm, lays out a serial dilution series, and turns a label ratio such as 1:10 into real volumes.

Determinant of a square matrix from 2 x 2 up to 6 x 6, with every row operation, the pivots and the sign from the row swaps written out.

Totals a dental implant quote line by line, from the post and crown to extractions and grafting, then applies insurance and a payment plan.

Compares keeping the debts you have against clearing them with one consolidation loan, showing both monthly payments and both total interest figures.

Applies the Payne albumin correction to a total serum calcium result, in mg/dL or SI units, with the formula, its assumptions and its limits stated.