OpenSTEMTool — Free University Scientific Calculators & Graphing

155 free university scientific calculators, graphing tools, and numerical analyzers across 38 academic departments. 100% free, private browser-based computations.

Perform accurate computations in mathematics, statistics, physics, chemistry, computer science, biology, and engineering. All numerical models execute locally in your browser with formula derivations, parameter tables, and export options.

Search all 155 calculators · Explore 38 academic departments

Data & Research

• Scientific Graph Studio — Create publication-friendly charts from measurements
• CSV Data Explorer — Inspect and transform measurements
• Regression & Curve Fitting — Fit models and inspect their residuals
• Uncertainty Propagation — Calculate measurement error correctly
• Descriptive Statistics — Summarize numerical distributions
• Scientific Report Builder — Generate structured reproducible reports
• Z-Score Calculator — Standardize a measurement using population mean and standard deviation.
• Standard Error of the Mean — Calculate uncertainty of a sample mean from sample SD and sample size.
• Normal Distribution PDF — Compute the probability density of a normal random variable.
• Binomial Probability Calculator — Calculate P(X=k) for a binomial model with n independent Bernoulli trials.
• Poisson Event Probability — Calculate the probability of k events from a Poisson process.
• Normal Approximation Confidence Interval — Compute a two-sided normal 95% confidence interval for a mean.
• Coefficient of Variation — Calculate relative dispersion from mean and standard deviation.
• Bayes Theorem Calculator — Calculate posterior probability from prior, sensitivity and false-positive rate.
• Proportion Sample Size (Approximate) — Estimate sample size for a two-sided 95% proportion interval.
• Pearson Correlation Calculator — Calculate Pearson r and covariance from paired numerical measurements.
• Discrete Expected Value — Compute expectation and variance from values and corresponding probabilities.

Mathematics

• 2D Function Grapher — Plot mathematical functions with adjustable parameters
• Calculus Explorer — Numerical derivatives and definite integrals
• 2D/3D Vector Explorer — Dot, cross products and spatial relationships
• Matrix & Linear System Solver — Solve small systems of simultaneous equations
• Eigenvalues & Transformations — Explore transformations of the XY plane
• 3D Surface Grapher — Explore multivariable functions
• Fourier & Signal Explorer — Explore harmonic approximations and signals
• Quadratic Equation Discriminant — Compute real roots of ax²+bx+c=0 and the vertex.
• Triangle Area (Heron) — Calculate triangle area from three side lengths.
• Circle Geometry — Calculate the circumference and area of a circle.
• Sphere Geometry — Compute volume, diameter, and surface area of a sphere.
• 2D Distance & Midpoint — Find distance and midpoint between two Cartesian points.
• Polar to Cartesian Coordinates — Convert polar coordinates to x and y Cartesian coordinates.
• Arithmetic Sequence Calculator — Find the nth term and sum of an arithmetic progression.
• Geometric Sequence Calculator — Calculate nth term and finite geometric series sum.
• Rectangular Pyramid Volume — Calculate volume of a rectangular pyramid.
• Trapezoid Area — Compute area of a trapezoid from parallel sides and perpendicular height.
• Two-Point Line Calculator — Find slope and intercept of a line through two points.
• Percentage Change Calculator — Measure absolute and percentage change between two measurements.

Physics

• Pendulum & Oscillation Analyzer — Model pendulum periods and extract gravity
• Projectile Motion Visualizer — Model ideal ballistic trajectories
• Interference & Diffraction — Explore optical intensity patterns
• Electric Field Visualizer — View electric fields from stationary point charges
• Kinetic Energy — Compute classical translational kinetic energy and momentum.
• Gravitational Potential Energy — Calculate near-surface gravitational energy relative to a reference height.
• Hooke Spring Energy — Calculate spring force magnitude and stored elastic energy.
• Centripetal Force — Compute inward force and acceleration for circular motion.
• Newtonian Gravitational Attraction — Calculate the magnitude of gravitational force between two masses.
• Escape Velocity — Calculate escape speed from an ideal spherical celestial body.
• Circular Orbit Period — Calculate period and speed of a circular Keplerian orbit.
• Photon Energy & Frequency — Convert wavelength into photon energy and frequency.
• de Broglie Wavelength — Calculate matter-wave wavelength for nonrelativistic momentum.
• Radioactive Decay — Calculate remaining fraction of a radioactive sample.
• Snell Refraction — Calculate the transmitted angle of light between two uniform media.
• Thin Lens Equation — Compute image location and magnification for a thin lens.
• Wave Speed, Frequency & Wavelength — Calculate frequency and period of a wave from speed and wavelength.
• Mass–Spring Oscillation — Calculate frequency and period for an ideal mass-spring oscillator.

Engineering

• RLC Circuit Analyzer — Explore resonance in a series RLC circuit
• Heat Transfer Analyzer — Calculate conduction and Newton cooling
• Axial Tensile Stress — Compute uniform axial stress from applied force and cross-sectional area.
• Engineering Strain — Calculate axial strain from extension and initial gauge length.
• Young Modulus from Stress and Strain — Estimate linear elastic modulus from measured stress and axial strain.
• Cantilever Beam Deflection — Calculate end deflection of an ideal cantilever carrying a tip point load.
• Linear Thermal Expansion — Compute change in bar length for a temperature change.
• Reynolds Number Calculator — Estimate Reynolds number for fluid motion through a characteristic length.
• Rotating Shaft Power — Calculate mechanical shaft power from torque and rotational speed.
• Ohm Law & Power — Calculate direct-current resistance, power and conductance.
• Two Resistors: Series & Parallel — Compute equivalent resistance of two ideal resistors.
• RC Charge & Discharge Model — Estimate charging voltage and discharge voltage in an ideal RC circuit.
• Inductive Reactance — Calculate reactance magnitude for an inductor at an AC frequency.
• Capacitive Reactance — Calculate magnitude of capacitive reactance at an AC frequency.
• Ideal Transformer Ratio — Calculate secondary voltage and current in an ideal transformer.
• Single-Phase AC Real Power — Compute real and apparent power from RMS voltage, current and power factor.
• Concrete Slab Volume — Estimate geometric concrete volume from length, width and thickness.
• Foundation Average Bearing Pressure — Estimate average contact pressure beneath a rectangular foundation.
• Euler Column Buckling Load — Calculate ideal elastic critical buckling force for a slender column.
• Darcy Porous Media Flow — Estimate Darcy volumetric flow through a porous cross-section.
• Manning Open Channel Velocity — Estimate mean flow velocity from Manning roughness and hydraulic radius.
• Aircraft Lift Estimate — Estimate aerodynamic lift using lift coefficient and dynamic pressure.
• Aerodynamic Drag Estimate — Estimate drag force using air density, reference area and drag coefficient.
• Ideal Rocket Equation — Calculate ideal velocity change from effective exhaust speed and mass ratio.
• Mach Number Calculator — Calculate Mach number and ideal-gas speed of sound.
• Process Tank Residence Time — Calculate nominal residence time of a perfectly mixed flow vessel.
• Single-Pass Reactor Conversion — Calculate reactant fractional conversion from inlet and outlet molar flow.
• Log Mean Temperature Difference — Calculate LMTD from positive heat-exchanger terminal temperature differences.
• Archimedes Buoyancy — Compute ideal buoyant force from displaced liquid volume.
• Fabric GSM Calculator — Calculate fabric mass per square meter from measured sample area.
• Yarn Linear Density (Tex) — Compute linear mass density of yarn in tex and denier.

Chemistry

• Acid–Base Titration Curve — Strong acid–strong base equilibrium model
• Mole and Mass Converter — Convert sample mass to amount of substance using molar mass.
• Solution Molarity Calculator — Calculate concentration from solute moles and total solution volume.
• Solution Dilution Calculator — Calculate volume of stock solution needed for an ideal dilution.
• Strong Acid pH — Estimate pH of a dilute monoprotic strong acid with water autoionization.
• Ideal Gas Law — Compute pressure of an ideal gas from temperature, moles, and volume.
• Arrhenius Temperature Dependence — Estimate the ratio of rate constants at two absolute temperatures.
• Chemical Reaction Percent Yield — Calculate percentage yield using actual and theoretical product masses.
• First-Order Chemical Kinetics — Model first-order concentration decay over time.
• Buffer pH (Henderson–Hasselbalch) — Estimate pH from acid pKa and conjugate base-to-acid concentration ratio.
• Ideal Osmotic Pressure — Compute dilute-solution osmotic pressure.
• Solution Mass Percentage — Calculate mass percentage of a solute in solution.

Computer Science

• Data Transfer Time — Estimate time to transfer a file at a constant effective data rate.
• Binary Storage Capacity — Compare decimal gigabytes and binary gibibytes.
• Audio PCM File Size — Estimate uncompressed pulse-code-modulated audio size.
• Raw Image Memory Estimator — Estimate uncompressed image memory requirement.
• Binary Shannon Entropy — Calculate information entropy of a Bernoulli source.
• Sigmoid Activation Function — Compute logistic sigmoid and its gradient for a neural-network input.
• Gradient Descent Step — Calculate one gradient descent step for a quadratic loss.
• 2D Cosine Similarity — Calculate cosine similarity and Euclidean distance between two vectors.
• Algorithm Growth Comparison — Compare logarithmic, linear and quadratic growth at a given input size.
• Compression Ratio Calculator — Measure storage saved by lossless or lossy compression.
• Network Round Trip Model — Estimate physical propagation latency plus a fixed processing delay.
• Shannon Channel Capacity — Estimate theoretical channel capacity from bandwidth and SNR.

Biological Sciences

• Exponential Bacterial Growth — Compute idealized population growth from doubling time.
• Logistic Population Growth — Model constrained population growth with carrying capacity.
• Hardy–Weinberg Allele Frequencies — Compute expected genotype proportions from an allele frequency.
• Michaelis–Menten Enzyme Rate — Calculate initial enzyme velocity from substrate concentration.
• DNA GC Content — Calculate GC fraction and base counts for a DNA sequence.
• Laboratory Dilution Factor — Calculate dilution factor from aliquot and final volume.
• Colony Forming Unit Estimate — Estimate CFU concentration from plate colony count and plated volume.
• Simpson Biodiversity Index — Compute Simpson’s diversity index from species abundances.
• Ecological Shannon Diversity — Calculate Shannon entropy of ecological species counts.
• Cell Culture Seeding Density — Estimate volume needed to seed a cell culture at a target cell count.

Earth & Space

• Astronomical Magnitude Difference — Compute flux ratio from a difference in apparent magnitudes.
• Astronomical Distance Converter — Convert parsecs into light-years and astronomical units.
• Tectonic Plate Displacement — Estimate accumulated plate displacement from a constant velocity.
• Exponential Atmosphere Pressure — Estimate atmospheric pressure in an isothermal hydrostatic atmosphere.
• Seawater Hydrostatic Pressure — Estimate pressure below sea surface using constant seawater density.
• Shallow Water Wave Speed — Estimate shallow-water gravity-wave propagation speed.

Health & Medicine

• Body Surface Area (Mosteller) — Compute anthropometric body surface area for classroom study, not clinical decisions.
• Body Mass Index (Arithmetic) — Compute an anthropometric ratio from measured height and mass.
• Disease Prevalence Percentage — Calculate prevalence in a defined population and time frame.
• Incidence Rate per Person-Time — Compute an event incidence rate from observed new cases and total person-years.
• Two-Group Relative Risk — Compare event risk in exposed and unexposed groups.
• Diagnostic Test Confusion Matrix — Calculate test sensitivity, specificity, and predictive values from counts.
• Drug Concentration Half-Life Model — Illustrate first-order pharmacokinetic concentration decline (not dosing advice).
• Macronutrient Energy Arithmetic — Estimate food energy from listed grams of protein, carbohydrate, and fat.

Economics & Finance

• Simple Interest Calculator — Calculate simple interest on principal over a specified number of years.
• Compound Annual Growth — Model compound annual growth or interest without cash flows.
• Contribution Break-Even Units — Calculate units needed to cover fixed costs at a constant price and variable cost.
• Gross & Net Profit Margin — Calculate gross margin and net profit margin from revenue and expenses.
• Net Present Value (Three Periods) — Discount three future cash flows and an initial investment.
• Compound Annual Growth Rate — Compute annualized growth rate between positive start and end amounts.
• Arc Price Elasticity of Demand — Compute midpoint arc elasticity between two price and quantity observations.
• Inflation Price Adjustment — Estimate future nominal price using a constant assumed annual inflation rate.
• Fixed-Rate Loan Payment — Calculate an illustrative equal monthly payment for an amortizing loan.
• Return on Investment — Compute an elementary gross return on an initial capital outlay.
• Herfindahl–Hirschman Index — Calculate market concentration from company market shares.

Agriculture & Food

• Fertilizer Nutrient Mass — Calculate supplied nutrient mass from fertilizer mass and concentration.
• Irrigation Volume from Water Depth — Calculate gross irrigation water volume for a field of known area.
• Seed Requirement Calculator — Estimate seed mass based on sowing rate per hectare.
• Timber Log Cylinder Volume — Estimate volume of a cylindrical log from length and average diameter.
• Animal Feed Conversion Ratio — Compute feed conversion ratio from consumed feed and mass gain.

Logic & Systems

• Little Law Queueing Estimate — Estimate average work-in-progress from throughput and elapsed system time.
• Boolean Logic Truth Table — Generate truth-table counts and example logic outputs for two binary inputs.

Humanities & Society

• Radiocarbon Age (Simplified) — Estimate radiocarbon age from measured fraction of original carbon-14.
• Mean Reaction Time — Summarize reaction-time measurements with mean and sample standard deviation.
• Chronological Year Span — Compute elapsed years between two Common Era dates (CE-only).
• Survey Response Rate — Compute valid survey completion and nonresponse rates.

The OpenSTEM Ecosystem

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Community & Contact

OpenSTEM Discord Server ↗ · Direct Email: shahriyarkarimsiam@gmail.com ✉