//precision calculators
Calculate with confidence.
Practical calculators with transparent formulas, explicit assumptions and results that explain themselves.
> 45 published · sourced · reviewed daily
try battery-runtime
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Featured calculators
Published tools exercise distinct formula families, precision behavior and review workflows.
01Battery Runtime CalculatorIdeal energy model v1.0Estimate runtime from capacity, voltage, usable energy and load.Electrical · Batteries02Ohm's Law CalculatorOhm's law v1.0Calculate resistance and power from voltage and current.Electrical · Circuits03Length ConverterPrecision sampleConvert through a single meter baseline with controlled display rounding.Converters · Length04Temperature ConverterKelvin baseline v1.0Convert Celsius, Fahrenheit and Kelvin through one baseline.Converters · Temperature05Concrete Volume CalculatorRectangular volume v1.0Calculate concrete volume from length, width and depth.Construction · Concrete06Weight / Mass ConverterKilogram baseline v1.0Convert mass units through one kilogram baseline with exact SI factors.Converters · Weight07Age CalculatorCalendar age v1.0Calculate calendar age and total elapsed days between dates.Time & Date08Data Storage ConverterDecimal bytes v1.0Convert bits and bytes through decimal SI prefixes (1 KB = 1000 B).Converters · Data
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Browse by task
Categories are compact editorial indexes, with availability derived from the registry.
01Electrical & ElectronicsBatteries, circuits and power.Electrical Power CalculatorCapacitor Charge CalculatorInductor Energy CalculatorSeries Resistors CalculatorParallel Resistor CalculatorBattery Runtime CalculatorOhm's Law CalculatorVoltage Divider CalculatorLED Series Resistor CalculatorCapacitor Energy CalculatorBattery Capacity CalculatorTransformer CalculatorPCB Trace Resistance Calculator13 published
02ConstructionMaterials, areas and volumes.Rectangle Area CalculatorConcrete Volume CalculatorCylinder Volume Calculator3 published
03ManufacturingMachining, tolerances and process.In preview
04MathEveryday and applied mathematics.Weighted Average CalculatorPercentage Error CalculatorLogarithm CalculatorExponent CalculatorSquare Root CalculatorAverage CalculatorCircle Area CalculatorStandard Deviation Calculator8 published
05Time & DateDurations, ages and scheduling.Day CounterCountdown CalculatorDate Difference CalculatorHours Between Times CalculatorWork Hours CalculatorBusiness Days CalculatorDecimal Hours CalculatorAdd Time CalculatorAdd or Subtract DaysAge CalculatorDuration Between Dates11 published
07ConvertersUnits, measures and conversions.Pressure ConverterData Storage ConverterFuel Economy CalculatorVolume ConverterArea ConverterLength ConverterTemperature ConverterWeight / Mass ConverterSpeed Converter9 published
//method first
Trust comes from the work behind the result.
- 01Defined methodInputs, outputs, formulas, scope and exclusions are explicit.
- 02Independent fixturesExpected results are established separately from the implementation.
- 03Versioned sourcesSources record publisher, version, date, jurisdiction and applicability.
- 04Controlled publicationRobots, sitemap, claims and advertising derive from one publication state.