Automotive, Diesel & Motorsports 6 calculators
- Eighth Mile to Quarter Mile Conversion CalculatorEmpirical ET conversion factors with a constant-power cross-checkHalf the drag strips in the country run an eighth mile and the other half run a quarter, so comparing two timeslips means…
- Engine Compression Ratio CalculatorSAE static compression ratio definitionStatic compression ratio is the single number that decides which fuel your engine can live on, and it is set entirely by…
- Engine Displacement CalculatorSwept-volume definition (SAE J1349 engine displacement)Engine displacement is the total volume every piston sweeps in one full revolution of the crank, and it follows directly from…
- EV Charging Cost CalculatorEPA fuel economy label convention (kWh per 100 miles)The energy that ends up in your battery is not the energy you pay for. Somewhere between 5% and 15% is lost in the charger, the…
- EV Charging Time CalculatorNFPA 70 (NEC) Article 625, 2023 editionCharging time is energy divided by the power that actually reaches the battery — and both halves of that fraction are easy to…
- EV Efficiency Calculator (kWh per Mile & MPGe)EPA fuel economy labelling, 40 CFR Part 600 (33.7 kWh per gallon equivalent)Electric vehicle efficiency is quoted four different ways — kWh per mile, Wh per mile, miles per kWh and kWh per 100 miles —…
Corporate Finance & Valuation 5 calculators
- Earnings Per Share (EPS) CalculatorASC 260 / IAS 33This calculator gives you basic earnings per share the way the accounting standards define it: net income less preferred…
- EBITDA CalculatorNon-GAAP measure (SEC Regulation G)EBITDA is earnings before interest, taxes, depreciation and amortisation: the profit a business produces from operations before…
- Economic Value Added (EVA) CalculatorStern Stewart EVA (economic profit)Economic value added is operating profit after tax minus a rent charged on all the capital the business uses. Accounting profit…
- Enterprise Value CalculatorEnterprise value bridge conventionEnterprise value is what it would cost to buy the whole operating business: the market value of the equity, plus every other…
- EV/EBITDA Multiple CalculatorComparable company analysis conventionEV/EBITDA is the multiple that dominates M&A, leveraged finance and private company pricing: enterprise value divided by…
Business, Marketing & E-commerce 4 calculators
- eBay Fee & Profit CalculatoreBay Selling fees schedule (US, managed payments)This calculator charges an eBay sale the way eBay does: a percentage final value fee on the whole amount the buyer pays, the…
- Economic Order Quantity (EOQ) CalculatorWilson EOQ model (Harris, 1913)Economic order quantity is the batch size that makes the sum of ordering cost and holding cost as small as it can be. Order in…
- Email Campaign ROI CalculatorCAN-SPAM Act, 15 U.S.C. §7701 et seq.An email campaign's revenue is a chain of five multiplications: list size, delivery rate, open rate, click-to-open rate and…
- Etsy Fee & Profit CalculatorEtsy fee schedule (US seller, Etsy Payments)This calculator adds up every fee Etsy deducts from one order — the $0.20 listing fee, the 6.5% transaction fee, payment…
Chemistry & Chemical Engineering 3 calculators
- Empirical Formula CalculatorIUPAC standard atomic weights (abridged, 2021)Give this calculator the mass percentages or the raw masses of the elements in a compound and it returns the empirical formula…
- Enthalpy of Reaction Calculator (Heats of Formation)Hess's law applied to standard enthalpies of formation at 298.15 KThe standard enthalpy change of any reaction is the sum of the formation enthalpies of the products minus the sum for the…
- Equilibrium Constant Calculator (Kc)IUPAC Green Book (3rd ed.) equilibrium conventionsThis calculator works the equilibrium problem in both directions. Give it the measured equilibrium concentrations of a reaction…
Electrical Trade & Electronics 3 calculators
- Electrical Power CalculatorIEEE Std 1459-2010 power quantity definitionsThis calculator separates the three numbers people routinely confuse: watts, volt-amperes and volt-amperes reactive. Give it a…
- Equipment Grounding Conductor Size CalculatorNEC 2023 (NFPA 70) 250.122Give this calculator the rating of the overcurrent device protecting the circuit and it returns the minimum equipment grounding…
- EV Charger Circuit & Load CalculatorNEC 2023 (NFPA 70) Articles 625, 210 and 220.57Electric vehicle supply equipment is a continuous load in the eyes of the National Electrical Code, so its breaker and its…
Arithmetic, Algebra & Number Theory 2 calculators
- Exponent CalculatorLaws of exponentsAn exponent is repeated multiplication, and everything else about exponents follows from keeping that idea consistent. This…
- Exponential Growth & Decay CalculatorGive this calculator a starting amount, a rate and an elapsed time and it projects the quantity forward — or backward, if…
Calculus, Linear Algebra & Discrete Math 2 calculators
- Eigenvalue & Eigenvector CalculatorCharacteristic polynomial det(A − λI) = 0Enter a 2×2 or 3×3 matrix and this calculator builds its characteristic polynomial, solves it exactly with the closed-form…
- Euler's Method CalculatorEuler and Heun (improved Euler) methodsThis calculator marches an initial value problem forward one step at a time and shows you the arithmetic. Enter the…
Computing, IT, Networking & Security 2 calculators
- Encryption Key Brute Force Time CalculatorNIST SP 800-57 Part 1 Rev. 5A symmetric key of k bits has 2 k possible values, and an exhaustive search finds the right one after half of them on average…
- Ethereum Gas Fee CalculatorEIP-1559 fee market (London upgrade)This calculator converts gas units and gwei prices into the fee you actually pay, using the EIP-1559 fee market that Ethereum…
Cooking, Baking & Brewing 2 calculators
- Edible Portion (EP) Cost CalculatorCulinary yield-test method (AP/EP)The price on the invoice is not what your food costs. Trim, bone and peel are weight you pay for and never serve, and cooking…
- Espresso Brew Ratio CalculatorMass brew ratio: beverage out over dry dose inEspresso is dialled in by mass, not volume: you weigh the dry dose going into the basket and the beverage coming out of the…
Crafts, Textiles, 3D Printing & Photography 2 calculators
- Embroidery Stitch Count EstimatorStitch-density geometry (area ÷ stitch footprint)Embroidery is quoted per thousand stitches, but you only learn the stitch count after the design has been digitised — which is…
- Epoxy Coverage & Flood Coat CalculatorUS gallon = 231 in³ exactly (NIST SP 811)Epoxy is sold by volume and applied by thickness, so the only calculation that matters is area × depth. This calculator does it…
Everyday Life & Household 2 calculators
- Electricity Bill CalculatorTiered (inclining-block) residential tariff structureEnter the kilowatt-hours on your meter and the rates from your tariff sheet, and this calculator rebuilds your electric bill…
- Emergency Water Storage CalculatorFEMA / Ready.gov one gallon per person per dayThe federal planning baseline is one gallon of water per person per day, half for drinking and half for food preparation and…
Sports, Games, Gambling Odds & Hobbies 2 calculators
- Elo Rating Change CalculatorFIDE Rating RegulationsEnter your rating, your opponents' ratings and how each game finished, and this calculator returns your expected score, the…
- ERA Calculator (Earned Run Average)MLB Official Baseball Rules, Rule 9.16Enter earned runs and innings pitched and this calculator returns earned run average scaled to a full game — nine innings for…