All SpecWhale tools

Estimate the water heater tank size needed based on household size using a common guideline.

Estimate minimum septic tank size based on number of bedrooms using a standard guideline.

Estimate chlorine needed to raise free chlorine level for a given pool volume.

Estimate total heat output from a quantity of firewood given BTU per cord.

Estimate the generator wattage needed to run a sum of appliance loads with a safety margin.

Estimate the number of moving boxes needed based on home size.

Estimate required moving truck cubic footage from number of rooms using an average volume guideline.

Calculate the exact total number of possible password combinations from character pool size and length.

Estimate effective throughput after VPN encryption overhead.

Estimate the approximate number of hashes needed for a 50% chance of collision using the birthday bound.

Estimate breach cost from number of records and an average cost per record.

Estimate total trip cost from per-day budget, trip length, and travelers.

Estimate the number of fuel stops needed for a road trip from total distance and vehicle range.

Calculate how much weight needs to move between bags to balance them under a weight limit.

Convert a percentage grade to an approximate 4.0-scale GPA value using a common linear mapping.

Calculate reading speed in words per minute and estimated time to read a document.

Calculate typing speed in words per minute from character count and time.

Calculate attendance percentage and how many classes can still be missed before falling below a target.

Allocate available study hours proportionally across two subjects by weight or difficulty.

Calculate the number of moles from a mass and known molar mass.

Calculate pH from hydrogen ion concentration.

Calculate pressure using the ideal gas law PV = nRT.

Calculate total resistance for two resistors in series and in parallel.

Calculate the output voltage of a two-resistor voltage divider.

Calculate the energy stored in a capacitor from capacitance and voltage.

Calculate the time constant of an RC circuit from resistance and capacitance.

Calculate the resistor value needed to safely drive an LED from a supply voltage.

Calculate three-phase electrical power from voltage, current, and power factor.

Calculate sine, cosine, and tangent of an angle in degrees.

Calculate the third side of a triangle using the Law of Cosines from two sides and the included angle.

Calculate a missing side using the Law of Sines from a known side and two angles.

Calculate the determinant of a 2x2 matrix.

Calculate the dot product of two 2D vectors.

Calculate the horizontal range of a projectile launched at an angle (no air resistance).

Calculate the time for an object to fall a given height under gravity.

Estimate income tax owed using a flat marginal rate above a threshold. Defaults are a worked example only -- enter your own current bracket numbers.

Calculate effective tax rate from total tax paid and total income.

Calculate commission earned from sales total and commission rate.

Estimate life insurance coverage needed using the DIME method (debt, income, mortgage, education).

Calculate the ratio of an insurance premium to the coverage amount it provides.

Estimate a dog's age in human years using a commonly cited formula (16 × ln(dog age) + 31).

Calculate a z-score for a measurement against a reference mean and standard deviation (e.g. growth charts).

Estimate daily formula intake using the common guideline of 2.5 oz per pound of body weight.

Calculate the amount of each component needed for a target mixing ratio and total volume.

Estimate free-space signal path loss in dB from distance and frequency.

Convert a power ratio to decibels using the 10·log10 formula, useful for audio and RF work.

Calculate the monthly contribution required to reach a savings goal by a target date.

Calculate the weighted average purchase price across two buy lots.

Calculate the price-to-earnings ratio of a stock.

Convert up to 16 binary digits to their exact decimal equivalent.

Convert a safely representable non-negative decimal integer to its exact binary representation.

Calculate the number of usable host addresses for a given subnet mask CIDR prefix.

Convert a total frame count and frame rate into elapsed HH:MM:SS plus remaining whole frames.

Calculate the megapixel count of an image from its pixel width and height.

Estimate download time from file size and connection speed.

Calculate age in total days from days lived input (use the date-based age calculator for calendar dates).

Calculate full-time-equivalent (FTE) from weekly hours worked.

Calculate the effective APR of a loan including a flat origination fee.

Calculate each party's proportional share of a combined expense based on income ratio.

Estimate the number of pavers needed for a patio area including waste allowance.