All SpecWhale tools

Estimate weekly and monthly diaper usage from daily change frequency.

Estimate monthly formula cost from daily ounces consumed and price per ounce.

Project future college costs from today's cost, an inflation rate, and years until enrollment.

Calculate the average cost per guest from a total wedding budget and guest count.

Estimate a long-distance moving cost from weight, distance, and a per-pound-per-mile rate.

Calculate the derivative of a quadratic function at a given x value.

Calculate the definite integral of a quadratic function between two bounds.

Calculate the average rate of change of a function between two points.

Calculate the sum of the first n terms of a geometric series.

Calculate the sum of the first n terms of an arithmetic series.

Calculate the probability of exactly k successes in n independent trials.

Calculate the Poisson probability of observing exactly k events given an average rate λ.

Calculate the probability of a specific outcome occurring n times in a row.

Calculate the union and unique-only counts for two overlapping sets.

Split a bill between two people proportionally to what each person ordered.

Split rent proportionally between two roommates based on their room's square footage.

Calculate a weekly grocery budget per household member from a total monthly budget.

Convert a dotted-decimal subnet mask's total bit count to CIDR prefix notation.

Calculate the percentage of available bandwidth currently in use.

Calculate the maximum sustained requests per second allowed under a rate limit.

Calculate uptime percentage and allowed downtime from total time and downtime minutes.

Estimate page load time from total page weight and effective connection speed.

Estimate monthly electricity cost from average daily kWh usage and rate.

Calculate annual electricity savings from switching to LED bulbs.

Estimate annual heating cost savings from lowering the thermostat by a number of degrees (1% savings per degree, common DOE guideline).

Calculate the payback period for an energy-efficient appliance from extra upfront cost and annual savings.

Calculate the present-day price of a zero-coupon bond from face value, yield, and years to maturity.

Estimate a bond's approximate yield to maturity from coupon, price, face value, and years.

Calculate the fixed monthly payout from an annuity balance over a set number of years.

Calculate the present value of a perpetuity from periodic payment and discount rate.

Calculate share quantity to buy based on account risk percentage and stop-loss distance.

Calculate the risk-to-reward ratio of a trade from entry, stop-loss, and target prices.

Calculate the breakeven stock price for a long call option.

Calculate overall portfolio return from two asset weights and their individual returns.

Estimate current pregnancy week from days remaining until the due date (280-day full term).

Estimate the likely ovulation day from the typical cycle length (ovulation ≈ 14 days before next period).

Calculate growth rate per month between two height or weight measurements.

Sum three independent scored categories into a total score, useful for clinical or assessment scoring scales.

Calculate customer acquisition cost from total marketing spend and new customers gained.

Calculate the ratio of customer lifetime value to customer acquisition cost.

Calculate month-over-month recurring revenue growth rate.

Calculate click-through rate from clicks and impressions.

Calculate the average cost per click from total ad spend and total clicks.

Calculate days sales outstanding from accounts receivable and total credit sales over a period.

Estimate daily dog food portion using a common 2-3% of body weight guideline.

Estimate fish stocking capacity using the common 1 inch of fish per gallon guideline.

Calculate torque from horsepower and engine RPM using the standard automotive formula.

Calculate gear ratio and output speed from input speed and tooth counts.

Estimate speedometer error percentage from original versus new tire diameter.

Calculate total engine displacement from bore, stroke, and number of cylinders.

Calculate alcohol units in a drink from volume and ABV percentage (UK units standard).

Estimate blood alcohol content using the Widmark formula from grams of alcohol consumed, body weight, and time.

Estimate remaining caffeine in the body after a given time using a 5-hour average half-life.

Calculate a medication dose from a mg-per-kg rate and body weight. For reference only — always confirm dosing with a clinician.

Calculate IV infusion drip rate from total volume, infusion time, and drop factor.

Estimate glomerular filtration rate using a simplified CKD-EPI style formula from serum creatinine, age, and sex.

Calculate moles of product from moles of reactant and a balanced equation's mole ratio.

Calculate percent yield from actual and theoretical yield in a chemical reaction.

Simplify a two-element mole ratio by dividing by the smaller value (for empirical formula determination).

Estimate the AC tonnage needed for a home using a standard 20 BTU per sq ft rule of thumb.