Calculators
Free online calculators for the numbers that come up in everyday life and work, all instant and private in your browser. Work with percentages using the percentage calculator, percentage increase and percentage decrease tools. Handle dates and time with the age calculator, days between dates, days until a date and hours between times calculators. For money and health there is a tip calculator, discount calculator, sales tax calculator and BMI calculator. Every calculator is free, needs no signup, and shows its result as you type.
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Online CounterUse a tally counter to count anything with one tap.Normal Distribution CalculatorCalculate probability below, between and above entered bounds for a normal model with visible z-scores.Mechanical Power CalculatorConvert work over time into average watts, kilowatts and mechanical horsepower without hidden efficiency.Hydrostatic Pressure CalculatorCalculate gauge and absolute pressure at depth for a static constant-density fluid.Rectangle CalculatorCalculate rectangle area, perimeter and diagonal from positive length and width measurements.Sample Size CalculatorEstimate completed responses for a proportion from confidence, margin, prevalence and population inputs.Margin of Error CalculatorEstimate an uncorrected normal-approximation margin for a sample proportion and confidence level.Trapezoid CalculatorCalculate trapezoid area, entered perimeter and midsegment from bases, height and side lengths.Cylinder CalculatorCalculate volume, total surface area and lateral area for a closed right circular cylinder.Linear Thermal Expansion CalculatorEstimate signed length change, final length and relative expansion from temperature change.Variance CalculatorCalculate population variance, sample variance and sample standard deviation from a browser-local number list.Rectangular Prism CalculatorCalculate box volume, surface area and space diagonal from three perpendicular edge lengths.Speed Distance Time CalculatorSolve any one value in the distance, average-speed and elapsed-time relationship with explicit units.Circumference CalculatorCalculate circle circumference, diameter and area from one positive radius in any consistent unit.Confidence Interval CalculatorEstimate a two-sided mean interval from sample mean, standard deviation, size and a preset level.Density Mass Volume CalculatorSolve for density, mass or volume from the other two values while keeping the unit relationship explicit.Reverse Percentage CalculatorRecover an original value from the final amount and a known percentage increase or decrease.Right Triangle CalculatorSolve all three sides from one acute angle and one known side, with area and complementary angle checks.Percentage Point Change CalculatorSeparate direct percentage-point movement from relative percent and basis-point changes.Trigonometry CalculatorCalculate sine, cosine and tangent together from an angle entered in degrees or radians.Complex Number CalculatorAdd, subtract, multiply or divide two complex numbers entered as separate real and imaginary parts.Gravitational Potential Energy CalculatorCalculate near-surface potential-energy change and weight from mass, height change and gravity.Ideal Gas Law CalculatorSolve PV equals nRT for pressure, volume, amount or absolute temperature with fixed SI units.Matrix Determinant CalculatorCalculate the determinant and trace of an entered three-by-three matrix and identify singular cases.Download Time CalculatorEstimate how long a file download will take.CTR CalculatorCalculate click-through rate from clicks and impressions.Emergency Fund CalculatorCompare essential monthly expenses and target months with current liquid emergency savings.Final Grade CalculatorFind the exam score needed for your target grade.Hourly to Salary CalculatorConvert hourly pay into annual salary.Loan Amortization CalculatorEstimate fixed monthly loan payments.Mortgage Refinance CalculatorCompare current and new mortgage payments.Overtime CalculatorCalculate regular pay, overtime pay and total pay.Rent Affordability CalculatorEstimate a comfortable monthly rent.Bandwidth CalculatorEstimate daily and monthly bandwidth.Bitrate CalculatorCalculate average bitrate from size and duration.Break Even CalculatorCalculate break-even units and revenue.Conversion Rate CalculatorCalculate conversions as a percentage.Cost Per Acquisition CalculatorCalculate CPA and revenue comparison.Cost Per Lead CalculatorCalculate CPL from spend and leads.Dimensional Weight CalculatorCalculate shipping dimensional weight.Fuel Cost CalculatorEstimate trip fuel cost.Profit CalculatorCalculate gross profit, net profit and margin.Property Tax CalculatorEstimate annual and monthly property tax.ROAS CalculatorCalculate return on ad spend.Salary to Hourly CalculatorConvert annual salary into hourly pay.Unit Price CalculatorCompare price per unit.Video File Size CalculatorEstimate video file size from bitrate and length.Audio File Size CalculatorEstimate audio file size from bitrate and length.