Everyday Life & Household 5 calculators
- Wallpaper Roll CalculatorUS double-roll bolt (20.5 in × 33 ft)Wallpaper is not bought by area, it is bought by drops — full-height strips cut from a bolt. This calculator counts how…
- Water & Sewer Bill CalculatorAWWA M1 rate-structure conventionsYour water utility does not charge you one price per gallon. It charges a fixed meter service fee, then a volume rate that…
- Water Softener Sizing CalculatorNSF/ANSI 44 salt-efficiency rating; ion-exchange resin capacity dataA water softener is sized in grains of hardness, not gallons per minute. This calculator multiplies your household's daily…
- Wedding Budget Allocation CalculatorPercentage-of-budget allocationA wedding budget fails in one of two ways: the categories are never given numbers, or the numbers are given and then the guest…
- Wind Chill CalculatorNWS / Environment Canada 2001 wind chill indexWind chill is the temperature that still air would have to reach to strip heat from bare skin as fast as the wind is stripping…
Plumbing, Piping & Hydraulics 4 calculators
- Water Heater Recovery Rate CalculatorSensible heat method, 8.33 BTU per gallon per FRecovery rate is how fast a storage water heater replaces what you have drawn off, in gallons per hour at a stated temperature…
- Water Heater Size Calculator (First Hour Rating)DOE first hour rating methodA storage water heater is sized on one hour, not one day: the busiest hour the household ever puts it through. Add up the hot…
- Water Service & Distribution Pipe Size CalculatorIPC Appendix E friction-loss segment methodThis calculator sizes a water service or distribution main the way a plan reviewer checks it: build a pressure budget, spend…
- Water Supply Fixture Unit (WSFU) CalculatorIPC Appendix E (Hunter's fixture-unit method)Count your fixtures, and this calculator returns the cold, hot and combined water supply fixture unit totals, then converts the…
Automotive, Diesel & Motorsports 3 calculators
- Weight Transfer CalculatorSAE J670 vehicle dynamics terminology; NHTSA static stability factorWeight transfer is what a vehicle's centre of gravity does to its tire loads the moment it accelerates in any direction, and it…
- Wheel Offset & Backspacing CalculatorISO 3911 wheel and rim terminologyOffset and backspacing describe the same thing two different ways, which is why comparing an ET35 wheel with a…
- Wheel Rate & Motion Ratio CalculatorMotion ratio defined as spring travel ÷ wheel travelA spring rate printed on a coil tells you nothing until you know where the spring sits. Suspension leverage divides both the…
Education, Grading & Test Scores 3 calculators
- Weighted GPA CalculatorWeighted 5.0 secondary scale (district convention; no national standard exists)Enter each course with its grade, its level and its credit value, and this calculator returns your weighted GPA alongside the…
- Weighted Grade CalculatorSyllabus weighted-category gradingList each assignment or category with its score and its syllabus weight and this calculator returns your course grade to date…
- Words to Pages Calculator12 pt Times New Roman, 1-inch margins baselineA page is not a fixed amount of writing. The same 1,000 words fill two pages in 12-point Times New Roman single spaced, four…
Energy, Solar, Sustainability & Environment 3 calculators
- Water Heating Energy & Cost CalculatorDOE Uniform Energy Factor (10 CFR Part 430)Water heating is usually the second-largest energy end use in a home, and it is the one people guess at most. This calculator…
- Wind Capacity Factor CalculatorCapacity factor definition; Weibull/Rayleigh wind speed distributionCapacity factor is the single number that tells you how hard a generating asset actually works: energy delivered divided by the…
- Wind Turbine Power Output CalculatorWind power equation P = ½ρAv³Cp; ISA atmosphere for air densityThis calculator applies the wind power equation — half the air density times swept area times the cube of wind speed, scaled by…
Aviation, Aerospace & Marine 2 calculators
- Wind Correction Angle & Heading CalculatorWind triangle (law of sines solution)This calculator solves the wind triangle. Give it the true course you want to track, your true airspeed, and the wind direction…
- Wing Loading CalculatorWing cube loading convention (model aviation)Wing loading is weight divided by wing area, and it is the single number that best predicts how an aircraft will feel: how fast…
Chemistry & Chemical Engineering 2 calculators
- Weak Acid pH CalculatorKa equilibrium solved by exact charge balanceEnter the acid dissociation constant and the concentration you weighed out, and this calculator returns the pH, the equilibrium…
- Weak Base pH CalculatorKb equilibrium solved by exact charge balanceGive this calculator the base ionisation constant — as K b , p K b , or the K a of the conjugate acid — together…
Computing, IT, Networking & Security 2 calculators
- WCAG Color Contrast Ratio CalculatorWCAG 2.2 SC 1.4.3, 1.4.6 and 1.4.11Enter a foreground and a background colour and this calculator returns the WCAG contrast ratio between them, the relative…
- Wildcard Mask Calculator (ACL)Cisco IOS access-list and OSPF network syntaxA wildcard mask is a subnet mask turned inside out: every bit that must match is a 0, and every bit the router should ignore is…
Construction, Carpentry & Concrete 2 calculators
- Wall Stud Count CalculatorIRC R602 wood wall framingEnter a wall length, a height and an on-centre spacing and this calculator returns the full stick count: layout studs, the…
- Wheelchair Ramp Slope Calculator (ADA 1:12)2010 ADA Standards for Accessible Design, Section 405An accessible ramp is governed by two limits, not one. The slope cannot exceed 1:12, and no single run may rise more than 30…
Electrical Trade & Electronics 2 calculators
- Watts to Amps CalculatorNFPA 70 (NEC) 2023Convert power to current, or current back to power, for DC, single-phase AC and three-phase AC circuits. Enter the watts (or…
- Wire Size & Ampacity CalculatorNEC 2023 (NFPA 70), Table 310.16 with 110.14(C), 240.4 and 310.15Enter the load, the conductor material and the conditions the conductor will live in, and this calculator returns the smallest…
Insurance & Risk Management 2 calculators
- Wind, Hail & Hurricane Deductible CalculatorPercentage deductible endorsements on homeowners formsA percentage deductible is not a percentage of your claim. It is a percentage of your Coverage A dwelling limit , which means…
- Workers Comp Experience Modifier (EMR) CalculatorNCCI Experience Rating Plan Manual for Workers CompensationYour experience modifier multiplies every dollar of workers compensation manual premium you pay, so a mod of 1.30 on a $250,000…
Legal, Claims & Settlements 2 calculators
- Workers Comp Permanent Disability CalculatorLongshore and Harbor Workers' Compensation Act, 33 U.S.C. §908(c)A permanent partial disability award is arithmetic, not negotiation. Three numbers produce it: your average weekly wage…
- Wrongful Termination Damages CalculatorTitle VII, 42 U.S.C. §2000e-5(g)Employment damages divide cleanly in two. Back pay runs from the termination to the day of trial or settlement and is reduced…
Physics: Mechanics, Waves & Thermodynamics 2 calculators
- Wave Speed, Wavelength & Frequency Calculatorv = fλ; c = 299,792,458 m/s (SI exact)Every wave obeys one relation: speed equals frequency times wavelength. Choose which of the three you want, pick a medium —…
- Work Done by a Force CalculatorMechanical work, W = F·d·cos θ (SI joule per NIST SP 811)Work in physics means force multiplied by the distance moved in the direction of that force, and this calculator gives it to…