AnythingOnline / Free calculators and utilities

Engineering & Science calculators

Choose a task below. Check each calculator’s assumptions and units before using its result.

Food Water Activity BET GAB Isotherm Calculator

Determine equilibrium moisture content, water activity ($a_w$), BET and GAB monolayer moisture capacity, and critical microbial stability thresholds.

Forchheimer Non-Darcy Flow Gradient Calculator

Petroleum reservoir engineering & high-rate gas wells: Compute the non-Darcy coefficient ($\beta$), viscous vs inertial pressure gradients, Forchheimer number ($Fo$), and critical Darcy velocity limit ($v_c$).

Forklift Capacity Calculator - Load Center & Derate Chart

Determine safe derated lifting capacity when handling oversized pallets, long stock, or front-end attachments beyond standard 24-inch centers.

Formwork Pressure Calculator - ACI 347 Lateral Pour Rate

Calculate maximum lateral formwork pressure (psf) using ACI 347-14 standards based on vertical pour rate, mix temperature, and wall height.

Foundation Dynamic Soil Impedance Calculator

Structural dynamics & earthquake engineering: Calculate Gazetas dynamic foundation impedance functions—static stiffness ($K$), dynamic stiffness modifier ($k(\omega)$), and radiation damping ($C$)—for surface footings.

Four-Factor Formula k-Infinity Calculator

Determine the infinite multiplication factor ($k_\infty = \epsilon \cdot p \cdot f \cdot \eta$) and effective multiplication ($k_{eff}$) across fuel enrichment and moderator regimes.

Four-Point Probe Sheet Resistance Calculator

Semiconductor wafer metrology & doping characterization: Compute sheet resistance ($R_s$), bulk resistivity ($ ho$), and active carrier concentration from four-point probe ($V/I$) measurements.

Four-Wave Mixing WDM Penalty Calculator

Nonlinear Optical Networking: Calculate Four-Wave Mixing (FWM) phase mismatch ($\Delta\beta$), generation efficiency ($\eta$), and crosstalk power ($P_{FWM}$).

Four-Wave Mixing WDM Phase Matching Calculator

Nonlinear fiber optics & DWDM telecommunications: Model Four-Wave Mixing (FWM) intermodulation sidebands, phase-matching efficiency ($\eta$), nonlinear crosstalk, and generated idler power.

Frac Tank Volume Calculator - BBL Gauge & Fluid Height

Convert manual gauge dipstick measurements into barrels, gallons, and total fluid payload tonnage for 500 BBL standard and V-bottom frac tanks.

Fracture Fluid Viscosity Calculator - Crosslinked Gel n

Model shear-thinning non-Newtonian behavior of linear guar, crosslinked borate gels, and viscoelastic surfactants using the Ostwald-de Waele power-law equation.

Francis Turbine Calculator - Specific Speed Sigma Sizing

Calculate Francis turbine specific speed, runner inlet diameter, critical Thoma cavitation sigma, and maximum allowable setting height above tailwater per USBR.

Francis Turbine Specific Speed & Cavitation Calculator

Determine kinematic specific speed (nq), Thoma cavitation parameter (σ_c), and draft tube setting height to prevent runner blade pitting.

Free Aquarium CO2 Calculator

Determine dissolved carbon dioxide (PPM / mg/L) from pH and Carbonate Hardness (KH) to optimize aquatic plant growth and prevent fish asphyxiation.

Free Brick and Mortar Calculator

Estimate total bricks, cubic feet of mortar, and premixed 80lb mortar bags needed for retaining walls, garden planters, and masonry facades.

Free CO2 Tank Weight & Runtime Calculator

Determine remaining liquid CO2 by scale weight, convert to gas volume (SCF & Liters), and calculate remaining hours or months of runtime.

Free Concrete Slab & Bag Yardage Calculator

Calculate cubic yards and exact 80lb/60lb premix bags with waste buffer.

Free Daily Light Integral (DLI) Calculator

Convert Photosynthetic Photon Flux Density (PPFD) and photoperiod hours into Daily Light Integral (DLI in mol/m²/day) to hit exact crop growth targets.

Free Epoxy Resin Ratio & Volume Calculator

Calculate Part A and Part B mix weights, volume, and exotherm cure limits.

Free Epoxy River Table Calculator

Calculate exact epoxy resin volume, Part A & Part B weights, wood absorption buffer, and maximum safe single pour depths.

Free Greenhouse Heater Calculator

Determine heating requirements in BTU/hr and Kilowatts to keep seedlings alive through freezing winter nights based on glazing thermal U-values.

Free Microgreens Seed Density Calculator

Calculate precise seeding weights in grams, blackout days, light cycle duration, and expected harvest yield for standard 1020 and 1010 trays.

Free Surface Effect Virtual GM Loss Calculator

Determine virtual rise in center of gravity ($GG_1$), second moment of liquid surface area ($i_T$), and longitudinal bulkhead subdivision benefits for slack tanks.

Free Woodworking Board Foot Calculator

Calculate exact board feet (BF) volume, account for rough milling scrap waste, and estimate total hardwood lumber project cost.

Free-Space Optical Link Budget Calculator

Satellite & Free-Space Optical (FSO) Communications: Compute diffraction-limited telescope gains, free-space path loss, received optical power ($P_r$), and link margin.

Freeze Drying Primary Sublimation Calculator

Pharmaceutical Lyophilization: Model vial heat transfer coefficient ($K_v$), ice sublimation rate, drying duration, and critical collapse temperature ($T_c$) safety margin.

Fresnel Reflection & Transmittance Calculator

Interface wave optics: Calculate s-polarized and p-polarized Fresnel reflection coefficients (\(R_s, R_p\)), Brewster angle (\(\theta_B\)), and critical angle (\(\theta_c\)).

Froth Flotation Recovery & Grade Calculator

Calculate mineral recovery ($R$), mass yield ($Y$), enrichment ratio ($ER$), Gaudin separation efficiency ($SE$), and flotation kinetic rate constants.

Fuel Cell Hydrogen Consumption Calculator

Fuel cell systems engineering: Calculate electrochemical hydrogen and oxygen consumption rates via Faraday's Law, excess stoichiometric flow ($lambda$), and mission storage requirements.

Furnace Radiative Heat Transfer Calculator

Industrial furnace thermal rating: Calculate gas emissivity (\(\epsilon_g\)), radiant exchange factor, tube heat flux, and Lobo-Evans radiant absorbed heat duty.

Fusion Plasma Lawson Triple Product Calculator

Thermonuclear Fusion Power: Compute the Lawson triple product ($n_e T_i \tau_E$), empirical confinement scaling (IPB98(y,2)), fusion gain ($Q = P_{fus}/P_{aux}$), and ignition threshold.

Gait Joint Moment Inverse Dynamics Calculator

Human motion analysis & clinical gait mechanics: Compute sagittal plane ankle and knee joint moments ($M_{\text{joint}}$) and Achilles tendon tension from force plate ground reaction forces ($GRF$).

Galvanic Cathodic Protection Sizing Calculator

Offshore & Marine Corrosion Engineering: Size sacrificial anode mass ($M$), quantity, circuit resistance ($R_a$), and current output per DNV-RP-F103.

Gamma Radiation Shielding Attenuation Calculator

Compute broad-beam gamma-ray attenuation ($I = I_0 \cdot B \cdot e^{-\mu x}$), linear attenuation coefficients, Half-Value Layers (HVL), and required shield thickness.

Gamma Radiation Shielding Calculator

Radiation protection physics: Calculate narrow-beam and broad-beam gamma attenuation, Half-Value Layers (HVL), Tenth-Value Layers (TVL), and Taylor buildup factors.

Gas Dispersion Impeller Flooding Calculator - Nienow Flg

Determine gas-liquid dispersion hydrodynamic regimes (flooded, loaded, complete dispersion) and gassed power draw (Pg/P0) per Nienow & Smith.

Gas Generator Turbopump Power Calculator

Liquid rocket propulsion cycles: Calculate fuel and oxidizer pump hydraulic and shaft powers, required gas generator turbine drive flow, and cycle specific impulse penalty.

Gas Hydrate Equilibrium Temperature Calculator

Subsea Flow Assurance: Calculate hydrate dissociation temperature ($T_{hyd}$), chemical inhibition suppression ($\Delta T_{dep}$), and subcooling risk margins.

Gas Hydrate Formation Calculator - Hammerschmidt Sizing

Calculate natural gas hydrate equilibrium formation temperature, required temperature depression, and thermodynamic inhibitor injection rates (Methanol, MEG, DEG) per GPSA.

Gas Kick Migration Rate Calculator - Shut-In Bubble Rise

Model bubble slip velocity (ft/hr), surface pressure buildup rate (ΔP/Δt), and compute volumetric method lubrication bleed schedules.

Gas Lift GLR & Inflow Performance Nodal Calculator

Optimize gas injection rate, Gas-Liquid Ratio ($GLR$), flowing bottomhole pressure ($P_{wf}$), and identify the critical inflection point on the gas lift performance curve.

Gas Lift Injection Rate Calculator - GLR Optimum Sizing

Determine the economic optimum lift gas injection rate (MMscfd / Sm³/d) by identifying the peak of the Gas-Liquid Ratio (GLR) performance curve.

Gas Lift Mandrel Spacing & Valve Sizing Calculator

Determine side pocket mandrel installation depths, surface unloading valve closing pressures ($P_{vc}$), and point-of-injection design.

Gas Pipeline Capacity Calculator - Weymouth MMCFD Flow

Size high-pressure transmission lines and determine gas flow rate in MMCFD and SCFH using the industry-standard Weymouth hydraulic equation.

Gas Reservoir p/z Material Balance Calculator

Determine Original Gas In Place ($G$ / OGIP), gas compressibility factor ($Z$), ultimate recovery factor, and remaining reserves at abandonment pressure.

Gas Turbine Brayton Cycle Calculator

Aerothermodynamics: Calculate open Brayton cycle specific net work ($w_{net}$), thermal efficiency ($\eta_{th}$), back work ratio ($BWR$), and optimal pressure ratio ($r_p$).

Gas Turbine Exhaust Energy Calculator - Heat Recovery HRSG

Calculate exhaust gas mass flow rate (lb/hr), available sensible waste thermal energy (MMBTU/hr & MWth), and steam generation capacity for cogeneration and HRSG boilers.

Gas Turbine Fouling Calculator - Compressor Derate Sizing

Quantify axial compressor aerodynamic fouling losses, inlet mass flow reduction, heat rate degradation, and financial megawatt loss per ISO 3977.