Everyday Life & Household 8 calculators
- Tip CalculatorPre-tax gratuity conventionEnter the check subtotal, your local sales tax and the percentage you want to leave, and this calculator returns the tip, the…
- Tire Pressure Temperature Change CalculatorGay-Lussac's law; FMVSS No. 138Tire pressure is a gas law, not a mystery. The air sealed inside a tire keeps a fixed volume, so when the temperature falls the…
- Tire Tread Life Remaining CalculatorFMVSS 571.109 tread wear indicators; 2/32 in legal minimumTwo measurements are all you need to know how much life is left in a set of tyres: how deep the tread was when new, and how…
- Toilet Flush Water Usage CalculatorEPAct 1992 (1.6 gpf) and EPA WaterSense (1.28 gpf)Toilets are the largest single use of water inside a typical home, and the flush volume of a fixture installed before 1994 can…
- Transit Pass vs Driving Commute CalculatorIRC §132(f) qualified transportation fringeThis calculator puts a full year of commuting by car against a year of commuting by transit. The driving side counts fuel…
- Trip Daily Budget CalculatorA trip budget only works if you separate the money you commit before you leave from the money you spend while you are there…
- TV Mount Height Calculator16:9 screen geometryThis calculator gives you the one number you actually need at the wall: the height above the floor to drill the bracket holes…
- TV Size & Viewing Distance CalculatorSMPTE 30° and THX 36–40° horizontal viewing angleScreen size is not a matter of taste — it is a matter of geometry. A television fills a measurable slice of your field of view…
Automotive, Diesel & Motorsports 7 calculators
- Tire Diameter Calculator from Tire SizeETRTO / T&RA metric size designationType in a tire size such as 275/40R18 and this calculator returns the overall diameter in inches and millimetres, the sidewall…
- Tire Size Comparison CalculatorISO metric tire designation (P-metric / ISO 4000-1)Enter the size on your current tire and the size you are thinking about, and this calculator works out the difference in…
- Towing Capacity & Payload CalculatorSAE J2807 tow-vehicle rating practiceThe number in the brochure is not your towing capacity. Your real limit is whichever of four separate ceilings you hit first…
- Trailer Tongue Weight CalculatorSAE J684 hitch classes; 10–15% conventional / 15–25% fifth-wheel practiceTongue weight is the downward force the trailer coupler puts on the hitch ball, and it is set almost entirely by where the…
- Trap Speed Horsepower CalculatorTrap-speed cube law (empirical constant)Terminal speed at the end of a drag strip is set almost entirely by power and weight, which makes it the cheapest honest…
- Turbo Compressor Airflow (lb/min) CalculatorIdeal gas law with R_air = 53.35 ft·lbf/lbm·°RA compressor map has mass flow on one axis and pressure ratio on the other, so choosing a turbo means knowing both numbers for…
- Turbo Pressure Ratio CalculatorU.S. Standard Atmosphere 1976 for ambient pressurePressure ratio is the vertical axis of every compressor map, and it is not the same thing as boost. It is absolute pressure at…
Calculus, Linear Algebra & Discrete Math 4 calculators
- Tangent Line CalculatorPoint-slope form of the tangent line, y = f(a) + f′(a)(x − a)Pick a curve and a point on it, and this calculator returns the tangent line, the normal line perpendicular to it, and the…
- Taylor Series CalculatorTaylor's theorem with the Lagrange form of the remainderA Taylor polynomial matches a function's value and its first N derivatives at one chosen point, and then behaves like the…
- Trapezoidal Rule CalculatorComposite trapezoidal rule with the classical second-derivative error boundThe trapezoidal rule joins consecutive points on a curve with straight lines and adds the areas of the resulting trapezoids…
- Truth Table CalculatorClassical propositional logicType a propositional formula and this calculator enumerates every assignment of its variables, evaluates each sub-formula in…
Insurance & Risk Management 4 calculators
- Teen Driver Insurance Cost CalculatorDriver-class rating with assigned-vehicle allocationAdding a teenager does not multiply your whole premium. It reprices the share of the policy attributable to the vehicle they…
- Term Life Insurance Ladder CalculatorLevel term pricing per $1,000 of face amountYour need for life insurance is not level, so buying level coverage means paying for protection you have stopped needing. The…
- Term vs Whole Life Cost Comparison CalculatorNAIC Life Insurance Disclosure Model Regulation — interest-adjusted cost indexesComparing whole life against term by looking at the premiums is meaningless, because the two products deliver different things…
- Total Loss Settlement CalculatorTotal loss threshold and total loss formula conventionsWhen a vehicle is declared a total loss, the insurer does not pay to fix it — it pays what the vehicle was worth the moment…
Investing & Retirement 4 calculators
- Tax-Equivalent Yield CalculatorIRC §103 tax-exempt interest; §1411 NIITA 3.6% municipal bond and a 5.2% corporate bond are not comparable until you tax them. This calculator converts a tax-free…
- Tax-Loss Harvesting Savings CalculatorIRC §1211(b) and §1212(b)Realising a loss is only worth doing if you know what it offsets. This calculator applies the netting order the Internal…
- Time-Weighted Return CalculatorGIPS time-weighted rate of returnIf you added money to a portfolio partway through the year, its simple percentage change tells you almost nothing about how the…
- Traditional vs Roth IRA Comparison CalculatorIRC §219 (traditional IRA) & §408A (Roth)The choice between a pre-tax and a Roth contribution is a bet on one number: your marginal tax rate in retirement compared with…
Time, Date, Navigation & Astronomy 4 calculators
- Telescope Magnification CalculatorThin-lens telescope relations; 2×D and 7 mm exit-pupil conventionsEnter your telescope's focal length and aperture, then the eyepiece you plan to use, and this calculator returns the…
- Time Duration CalculatorISO 8601 time-of-day and duration conventionsEnter a start time and an end time and this calculator returns the elapsed span in hours, minutes and seconds, in decimal…
- Time Zone Converter CalculatorIANA Time Zone Database (tzdb) offset conventionsGive this calculator a date and time, the UTC offset of the zone it is written in and the UTC offset of the zone you want it…
- Twilight Times CalculatorUSNO twilight definitions (−6°, −12°, −18° solar altitude)Twilight is defined by how far the Sun sits below the horizon, not by how the sky looks, and the three standard thresholds are…
Agriculture, Livestock & Landscaping 3 calculators
- Topsoil Calculator (Yards & Tons)USDA NRCS soil bulk density conventions; 27 ft³ per cubic yardSoil is sold two ways — by the cubic yard from a landscape yard, by the ton off a scale — and the conversion…
- Tractor Fuel Use & Cost per Acre CalculatorASABE D497.7 Agricultural Machinery Management DataFuel is the field-operation cost you can actually predict, because diesel consumption per hour follows the engine load closely…
- Tree Height CalculatorTangent method (USDA Forest Service FIA field practice); OSHA 29 CFR 1910.266 felling clearanceYou cannot put a tape on a standing tree, so height is measured by trigonometry: stand a known horizontal distance away, read…
Aviation, Aerospace & Marine 3 calculators
- Takeoff Distance CalculatorCAA Safety Sense correction factorsTake-off distances in a flight manual are demonstrated numbers: a new aeroplane, a test pilot, a dry level paved runway and a…
- Top of Descent CalculatorRule of three / 3 degree glidepath geometryThis calculator tells you how far from the destination or crossing fix to start down, and how fast to come down once you do…
- True Airspeed (TAS) CalculatorICAO Standard Atmosphere (ISO 2533), compressible-flow airspeed relationsYour airspeed indicator measures dynamic pressure, not speed. As you climb into thinner air the same dynamic pressure…
Construction, Carpentry & Concrete 3 calculators
- Tile CalculatorTCNA Handbook / ANSI A108This calculator counts the tiles and the boxes a floor, wall or backsplash actually needs. It works from the effective tile…
- Tile Grout & Thinset CalculatorANSI A108 / TCNA Handbook installation practiceGrout demand is set by geometry: the narrower the tile, the more joint there is per square foot, and the volume scales with…
- Trench Excavation Volume CalculatorOSHA 29 CFR 1926 Subpart PEnter a trench length, bottom width and depth, choose vertical walls or an OSHA soil classification, and this calculator…
Cooking, Baking & Brewing 3 calculators
- Turkey Cooking Time CalculatorUSDA FSIS roasting guidanceEnter the weight of your bird, whether it is stuffed, and the time you want to carve. This calculator returns the roasting time…
- Turkey Size Per Person CalculatorUSDA cooking yields and refuse factors for whole poultryThe familiar rule of one to one and a half pounds of turkey per person hides the number you actually care about: how much…
- Turkey Thawing Time CalculatorUSDA FSIS thawing guidanceA frozen turkey needs days, not hours, and the single most common Thanksgiving failure is starting too late. This calculator…
Accounting & Financial Statement Analysis 2 calculators
- Total Asset Turnover Ratio CalculatorDuPont decomposition — efficiency termTotal asset turnover tells you how much revenue each dollar of assets produces. Enter net revenue and the opening and closing…
- Trial Balance Calculator & Debit-Credit CheckerDouble-entry bookkeeping proofA trial balance proves one thing: that every debit posted to your ledger has a matching credit. Enter your account balances by…
Corporate Finance & Valuation 2 calculators
- Terminal Value Calculator (Gordon Growth / Perpetuity Method)Gordon growth (perpetuity) terminal value methodTerminal value is everything your discounted cash flow model is worth after the explicit forecast stops, and in a typical…
- Times Interest Earned (Interest Coverage) CalculatorInterest coverage (EBIT basis)Times interest earned divides operating profit by the interest bill, so it says how many times over the year's earnings could…
Education, Grading & Test Scores 2 calculators
- Test Grade Percentage CalculatorPercentage grading with conventional 90/80/70/60 letter bandsEnter points earned out of points possible — or just the number of questions marked wrong — and this calculator returns the…
- Typing Speed Calculator (WPM)Five-character standard wordTyping speed is measured in standard words, and a standard word is five keystrokes including the space — not a real English…
Electrical Trade & Electronics 2 calculators
- Three-Phase Power CalculatorBalanced three-phase AC power relations (IEEE Std 1459)Give this calculator the line-to-line voltage, the power factor, and any one of line current, kilowatts or kilovolt-amperes…
- Transformer kVA Sizing CalculatorNEC Article 450 · ANSI/IEEE C57.12 rating seriesTell this calculator what your load is — in kVA, in kilowatts with a power factor, or as measured amps at the secondary voltage…
Geometry & Trigonometry 2 calculators
- Trapezoid Area & Perimeter CalculatorEnter the two parallel sides and the perpendicular height and this calculator returns the area, the midsegment and — if…
- Triangle Area CalculatorThis calculator finds the area of any triangle by whichever route your measurements allow: base and perpendicular height, three…
Industrial, Logistics & Plant Operations 2 calculators
- Takt Time Calculator (Customer Demand Rate)Lean production / Toyota Production System definition of taktTakt time is the beat your production has to match: net available working time divided by customer demand for that same period…
- Trucking Cost Per Mile Calculator (Owner-Operator)Fixed plus variable cost model, with deadhead adjusted onto loaded milesThis calculator turns your real monthly costs into a defensible cost per mile and then answers the question that actually…
Physics: Mechanics, Waves & Thermodynamics 2 calculators
- Thin Lens Equation & Magnification CalculatorThin lens equation, Gaussian (real-is-positive) sign conventionGive this calculator a focal length, an object distance and an object height, and it locates the image from 1/f = 1/d₀ + 1/dᵢ…
- Torque CalculatorMoment of a force, τ = r × F; SI and customary torque units per NIST SP 811Torque is the turning effect of a force about an axis, and it depends on three things: how big the force is, how far from the…
Plumbing, Piping & Hydraulics 2 calculators
- Tankless Water Heater Sizing CalculatorASHRAE service water heating methodA tankless water heater has no reserve to fall back on, so it is sized on two numbers and nothing else: the gallons per minute…
- Total Dynamic Head (TDH) CalculatorHazen-Williams (AWWA practice)Total dynamic head is the whole job you are asking a pump to do, expressed as a height of water. It is the vertical distance…
Sports, Games, Gambling Odds & Hobbies 2 calculators
- True Shooting Percentage CalculatorBasketball Reference / Dean Oliver shooting-efficiency definitionsTrue shooting percentage measures scoring efficiency across all three ways to score — two-pointers, three-pointers and free…
- TTRPG Dice Probability CalculatorEnter any dice expression - 1d20, 2d6, 8d10 - add your modifier and a target number, and this calculator returns the exact…
Unit & Measurement Conversion 2 calculators
- Tire Size to Inches Diameter CalculatorISO metric tire designation (ETRTO / Tire and Rim Association)A tire code such as 275/60R20 mixes two unit systems in five characters: 275 is the section width in millimetres, 60 is the…
- Torque Unit ConverterSI newton-metre; ISO 6789 for hand torque toolsTorque specifications arrive in whatever unit the manufacturer's home market uses: newton-metres on European and Japanese…