Worldwide context
Saved once here, used across the site.
Currency changes display only. Country selection guides tax input; no tax rate is guessed.
Equations with units attached
This collection brings together science calculators that expose units, constants, equations, and boundary conditions for classroom exercises, lab planning, and first-pass engineering estimates.
Start here
These are the clearest entry points for this collection. Open one first, then use the grouped map below when you need a more specific tool.
Coulomb friction force from coefficient μ and normal force.
Open calculator → sciencePressure from an applied force over a piston area, in pascals and kilopascals.
Open calculator → scienceWhat remains of a decaying sample after a given elapsed time.
Open calculator → scienceMean travel speed from distance and time, in km/h and m/s.
Open calculator → conversionConvert pressure among pascals, kilopascals, megapascals, bar, standard atmospheres, pounds per square inch, and millimeters of mercury.
Open calculator → technologyEstimate GPU memory for loading a language model from parameter count and quantization, and see which cards it fits.
Open calculator →Why this group exists
Units and model boundaries matter as much as the arithmetic. Keep a consistent unit system, check the scale of the result, and treat simplified models as a starting point for measurement or review.
Context
Science problem solving often follows a repeatable pattern: define a system, choose a model, substitute measured or supplied values, and test whether the result fits the model’s limits. The collection makes those stages readable on each page.
Worldwide use
Choose a display currency and country context when helpful, but keep units, rates, dates, definitions, and local rules explicit. Currency changes display only; country context never supplies guessed tax or legal rules.
A repeatable path
Learn before you calculate
These guides connect the collection to real planning questions and point back to the relevant tools.
Convert gold weight in grams, kilograms, or troy ounces into fine-gold content and an estimated metal value.
Move from factors and roots to a verified equation solution while keeping real and complex results, domains, and substitution checks visible.
Convert cubic centimetres into US fluid ounces, millilitres, US cups, and litres while keeping volume ounces separate from mass ounces.
Convert euro cents into euros, whole euros, and the remaining cent component without applying a foreign-exchange rate.
Calculator map
Tools are grouped by their catalog category. A calculator may be relevant to more than one collection, but every tool keeps one canonical page and one tested formula contract.
699 tools
Physics and chemistry quantities with textbook formulas: motion, force, energy, mechanics, gravity, optics, relativity, thermal radiation, circuits, measurement error, solutions, concentration, colligative properties, gases, and pH.
416 tools
Percentages, factors, fractions, equations, vectors, sequences, triangles, circles, and a safe scientific expression parser.
105 tools
Length, mass, temperature, area, volume, speed, angles, capacitance, and density with defined factors.
137 tools
Numbers behind computing and networks: storage units, number bases, transfer times, passwords, IPv4/IPv6 subnets, and web design math.
27 tools
Transparent environmental and sustainability scenarios for energy, materials, transport, food, water, and population models.
No. The calculator contract and result steps state the relevant units or fixed constants used by that tool.
No. It can support learning or an early estimate, but design, safety, compliance, and measured performance require qualified review.
