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Calculate current and dissipated power for an ideal ohmic resistor with positive resistance. This is a component model, not a wiring design.
Calculate DC electrical power. AC systems may require RMS values, phase information and power factor not represented here.
Add nonnegative ideal resistor values connected in series. Values must all use ohms.
Find equivalent resistance for positive ideal resistors in parallel. Zero resistance is excluded to avoid division by zero.
Calculate energy stored in an ideal capacitor. Capacitance is entered in microfarads and voltage in volts.
Estimate sensible heat with constant specific heat capacity and no phase change. A temperature difference in kelvin equals one in Celsius.
Estimate paint volume after deducting doors and windows from your area. Coverage depends on the product and surface condition.
Estimate whole packs of flooring including a waste allowance. Irregular cuts and installation pattern can change material needs.
Estimate whole tiles using nominal face dimensions. Grout spacing and cuts are not modelled individually.
Estimate concrete volume for a rectangular slab. This calculates material volume only and does not specify structural reinforcement.
Estimate loose gravel volume and mass using a supplier-provided bulk density. Compaction and moisture may change the actual quantity.
Estimate soil volume for a uniform layer. Settlement and compaction are excluded from the geometric volume.
Estimate whole bags for a uniform mulch layer. Bag volume and depth are converted to the same volume unit.
Estimate rolls from full-height strips. Include trimming in height; pattern repeats and openings require your own allowance.
Count posts for one open straight run with a post at each end. Gates, corners and closed loops need separate treatment.
Calculate slope percentage and angle from rise and horizontal run in the same unit. Material rules and local codes are not evaluated.
Divide a total rise into equal risers no higher than your target. Tread depth, landings and building-code compliance are not determined.
Estimate water volume in a rectangular pool using average water depth. Steps, curves and displaced volume are excluded.
Estimate filling time at a constant flow rate with no leaks or outflow. Supply pressure changes can alter actual time.
Estimate energy and variable usage cost from appliance power and time. Fixed fees, tax rules and changing tariffs are excluded.
Estimate consumption cost using one flat rate. Tiered tariffs, sewage charges and fixed fees are excluded.
Estimate fuel and cost at constant consumption. Include the full round-trip distance if you want a return journey estimate.
Calculate fuel economy from a measured distance and fuel quantity. Both outputs describe the same trip with inverse conventions.
Estimate charge time with a constant average power and efficiency. Real charging can taper; use average power rather than peak rating.
Estimate runtime from nominal energy and a usable-capacity allowance. Battery chemistry, temperature and current-dependent losses are not modelled.
Scale one ingredient in direct proportion to servings. Cooking time and temperature do not generally scale by the same factor.
Resize an image to a new width while preserving its aspect ratio. Rounded pixel height may cause a tiny ratio difference.
Estimate screen pixel density assuming square pixels and the stated active-display diagonal in inches.
Add or subtract calendar days, counting weekends and holidays. UTC date arithmetic prevents daylight-saving shifts.
Find the ISO weekday number for a Gregorian calendar date. Monday is 1 and Sunday is 7, independent of local timezone.
Find the ordinal day from 1 to 365 or 366. Leap days are included automatically.
Find the ISO week and week-year. Dates near New Year can belong to the preceding or following ISO year.
Return the number of days in a Gregorian year. Years divisible by 100 are common years unless also divisible by 400.
Find the length of a Gregorian calendar month, including February in leap years. Month numbers run from January 1 to December 12.
Count weekdays excluding the starting date and including the ending date. National and local public holidays are not removed.
Add Monday-to-Friday days after a starting date. Holidays are not excluded, so this is not a jurisdiction-specific deadline calculator.
Convert an hours-and-minutes duration into decimal hours. Thirty minutes is 0.5 hour, not 0.30 hour.
Subtract an unpaid break from each identical shift. This totals hours only and does not apply local overtime rules.
Convert work and heat energy. The calorie is the thermochemical calorie of exactly 4.184 joules, and kWh is energy rather than power.
Convert pressure units using standard atmosphere, bar and pound-force per square inch. Gauge and absolute references are not changed by unit conversion.
Convert newtons, kilonewtons, pound-force and kilogram-force. Kilogram-force uses standard gravity of 9.80665 m/s² and is not mass.
Convert radians, degrees, gradians and full turns. One turn is 2π radians, 360 degrees or 400 gradians.
Convert bits and bytes with explicit decimal and binary prefixes. MB means 1,000,000 bytes; MiB means 1,048,576 bytes.
Convert decimal bit rates and byte rates. One byte contains eight bits; network overhead is not included.
Convert cyclic frequency between hertz, prefixed hertz and revolutions per minute. Angular frequency in radians per second is a different quantity.
Convert acceleration using metres, centimetres or feet per second squared. Standard gravity g₀ is fixed at 9.80665 m/s².
Convert torque between newton-metres and force-length units. Although dimensionally similar to energy, torque is reported as torque, not joules.
Convert mass density rather than weight density. A gram per cubic centimetre equals 1,000 kilograms per cubic metre.
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