Electrical Trade & Electronics 3 calculators
- Ohm's Law CalculatorOhm's law and Joule's law (IEEE Std 280 quantity symbols)Pick the two quantities you already know — any two of voltage, current, resistance and power — and this calculator returns the…
- Op-Amp Gain CalculatorIdeal op-amp model with finite gain-bandwidth productPick a topology, enter the two resistors, and this calculator returns the closed-loop gain in volts per volt and in decibels…
- Optional Dwelling Load Calculation CalculatorNEC 2023 (NFPA 70) 220.82This calculator runs the optional dwelling load calculation of NEC 220.82 — the short method most designers reach for on a…
Industrial, Logistics & Plant Operations 3 calculators
- OEE Calculator (Overall Equipment Effectiveness)Nakajima TPM definition of OEE; SEMI E79 equipment efficiency measurementOEE multiplies three rates that each answer a different question: did the machine run when it was supposed to, did it run at…
- Oil & Gas Royalty Calculator (Net Revenue Interest & Monthly Check)Division order net revenue interest conventionA royalty check is the product of three things: how much of the drilling unit you own, what fraction of production your lease…
- OSHA Incident Rate Calculator (TRIR, DART & LTC)OSHA 29 CFR Part 1904 recordkeeping; incidence rates per 200,000 hoursEvery OSHA incidence rate is the same calculation with a different numerator: count the cases, multiply by 200,000, divide by…
Insurance & Risk Management 3 calculators
- Out-of-Network Balance Billing CalculatorNo Surprises Act (Consolidated Appropriations Act, 2021)An out-of-network bill has two independent parts and people conflate them constantly. Your cost share is the deductible and…
- Out-of-Pocket Maximum CalculatorACA cost-sharing limits, 45 CFR §156.130A family health plan carries four limits — an individual deductible, a family deductible, an individual out-of-pocket…
- Own-Occupation vs Any-Occupation Disability CalculatorThe definition of disability decides whether a policy pays, and it is worth more than any other clause on the contract. Under a…
Accounting & Financial Statement Analysis 2 calculators
- Operating Cash Flow Ratio CalculatorASC 230 / IAS 7 statement of cash flowsThe operating cash flow ratio tests liquidity with a figure the balance sheet cannot flatter: cash the business actually…
- Operating Profit Margin CalculatorSEC Reg S-X 5-03; Reg G for EBITDAOperating margin is the cleanest single measure of how good a business is at its actual business. Enter revenue, cost of goods…
Energy, Solar, Sustainability & Environment 2 calculators
- Off-Grid Battery Bank Amp-Hour CalculatorIEEE 1013 sizing methodThis calculator turns a daily watt-hour load into the amp-hour capacity of an off-grid battery bank, then works out how many…
- Off-Grid Daily Load Audit (Watt-Hours) CalculatorEvery off-grid, RV and marine solar design starts with one number: the watt-hours your loads consume in a day. This calculator…
Health, Fitness & Nutrition 2 calculators
- One Rep Max CalculatorEpley, Brzycki, Lombardi, Lander and O'Conner repetition-maximum equationsA one rep max is the heaviest load you can lift once with good technique, and estimating it from a set you have already done is…
- Ovulation & Fertile Window CalculatorCalendar method with the Wilcox six-day fertile windowThis calculator works out which day of your cycle you are likely to ovulate and which days make up the fertile window around…
Statistics & Probability 2 calculators
- One-Sample T-Test CalculatorStudent's t-testA one-sample t-test asks whether the mean of your sample is far enough from a reference value that chance alone is an…
- One-Way ANOVA CalculatorFisher's analysis of varianceOne-way ANOVA tests whether several group means could all have come from the same population. Paste each group's raw values…