AnythingOnline / Free calculators and utilities

Engineering & Science calculators

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

Ship Seakeeping Heave & Pitch Period Calculator

Calculate ship natural heave ($T_z$), pitch ($T_\theta$), and roll ($T_\phi$) oscillation periods, Doppler wave encounter frequency, and parametric resonance risk.

Ship Squat & Channel Clearance Calculator

Harbor & channel navigation safety: Calculate Bernoulli ship squat sinkage, bow/stern trim shift, and net Under-Keel Clearance (UKC).

Ship Squat & Shallow Water Sinkage Calculator

Determine dynamic ship squat ($S_{max}$), Bernoulli pressure drop in shallow waterways, under-keel clearance ($UKC$), and bow vs. stern trim changes.

Shockley-Queisser Limit Solar Cell Calculator

Determine the fundamental theoretical efficiency limit, cutoff wavelength ($\lambda_g$), thermalization losses, and open-circuit voltage ($V_{oc}$) from detailed balance physics.

Shotcrete Accelerator Calculator - Rebound Spray Loss

Determine alkali-free liquid accelerator dosing (GPM & total volume), early compressive strength progression, and overhead vs wall rebound loss.

Shunt Capacitor Inrush Current Calculator

Substation power factor correction & reactive power: Calculate back-to-back capacitor bank switching peak inrush current (I_peak), inrush frequency, and damping reactors.

Side Scan Sonar Target Height Calculator

Hydrographic surveying & seafloor imaging: Compute object height from acoustic shadow length ($L_s$), towfish altitude ($H$), slant range ($R_s$), and nadir blind zone width.

Sideband Cooling Optomechanics Calculator

Quantum macroscopic cooling: Calculate laser sideband cooling of mechanical resonators, initial thermal bath phonon population ($n_{\text{th}}$), net cooling rate ($\Gamma_-$), and quantum ground-state occupancy ($n_f < 1$).

Sieve Tray Flooding & Capacity Calculator

Hydraulic sizing of distillation column sieve trays: Calculate Fair capacity factor (\(C_{sb}\)), flooding vapor velocity (\(u_{flood}\)), column diameter (\(D\)), and % jet flood.

Sieve Tray Weeping Calculator - Minimum Vapor Velocity

Determine sieve tray weeping limit, minimum hole vapor velocity (m/s), vapor F-factor, and clear liquid head to prevent tray liquid dumping per Kister.

Silica Scaling Index Calculator - Geothermal Brine SSI

Determine amorphous silica solubility, Silica Saturation Index (SSI), and safe minimum reinjection temperature to prevent wellbore pipeline scaling.

Silo Arching & Ratholing Minimum Outlet Calculator

Determine critical cohesive arching outlet dimension ($B_{min}$) and stable rathole piping diameter ($D_{rh}$) based on powder shear cell yield strength.

Silo Wall Pressure Janssen & Walker Calculator

Compute Janssen vertical and horizontal wall pressures ($p_v$, $p_h$), Walker hopper transition stress, and Eurocode 1 (EN 1991-4) discharge overpressures.

Silt Density Index SDI Membrane Fouling Calculator

Determine ASTM D4194 Silt Density Index ($SDI_{15}$) and plugging rate percentage ($P_{30}$) to verify reverse osmosis feed water pretreatment compliance.

Single Screw Extruder Flow Rate Calculator

Determine drag flow ($q_d$), pressure backflow ($q_p$), net volumetric throughput ($Q$), and mass extrusion rate (kg/h) in the metering section.

Single-Flash Geothermal Power Calculator

Geothermal Power Thermodynamics: Optimize cyclone separator pressure ($P_{sep}$), steam quality ($x$), turbine power ($W_t$), and net thermal efficiency.

Sintering Dimensional Shrinkage Calculator

Calculate sintering shrinkage (\(S_L, S_V\)), compact-to-die cavity expansion sizing, final density, and ISO dimensional tolerance classes.

Slinky Loop Trench Calculator - Horizontal Geothermal Pipe

Determine horizontal geothermal slinky loop trench footage, coil pitch overlap, total HDPE pipe requirements, and excavation backfill cubic yardage.

Slope Stability Safety Factor Calculator

Geotechnical slope engineering: Calculate the factor of safety (FS) against planar translational slope failure under dry, partially submerged, and parallel seepage states.

Sludge Volume Index Calculator - SVI Settleability

Model activated sludge settleability: calculate Sludge Volume Index (SVI) in mL/g, diagnose filamentous bulking, and determine required RAS recycle flow rates.

Slug Catcher Sizing Calculator - Subsea Multiphase Volume

Determine required pipe finger diameter, number of storage fingers, and liquid surge capacity for transient pigging slugs and terrain-induced severe slugging.

Slug Catcher Volume Calculator - Finger Type Gas-Liquid

Determine required liquid surge retention volume (m³), number of storage fingers, and pipe diameter to handle pigging slugs and hydrodynamic transients.

Slurry Pipe Velocity Calculator - Durand Critical Settling

Determine Durand critical deposition velocity, safe slurry transport flow rates, and pipeline friction head loss to prevent pipe sanding.

Slurry Shield TBM Face Pressure Calculator

Hydro-Shield Tunneling: Calculate required air bubble plenum pressure, excess slurry pressure, bentonite penetration depth, and filter cake sealing stability.

Snow Drift Load Calculator - ASCE 7 Parapet Roof Surcharge

Calculate ASCE 7 balanced snow load, leeward and windward snow drift surcharge height (ft), peak drift load (psf), and drift horizontal width.

SOFAR Channel Sound Speed Calculator

Physical oceanography & underwater acoustics: Compute seawater sound velocity profiles (Mackenzie 9-term equation), SOFAR channel waveguide axis, and ray bending curvature.

SOFAR Sound Channel Ray Refraction Calculator

Deep ocean acoustics: Compute Snell’s law sound speed gradient ($dc/dz$), ray curvature radius, acoustic ray turning depths ($z_{\text{turn}}$), and SOFAR channel cycle skip distance.

SOFC Fuel Cell Nernst Efficiency Calculator

High-temperature ceramics electrochemistry: Compute the thermodynamic Nernst potential ($E_{Nernst}$), maximum theoretical efficiency ($\Delta G/\Delta H$), Area-Specific Resistance ($ASR$), and combined heat & power output.

Soil Falling Head Permeability Calculator

Soil Mechanics & Hydrogeology: Compute hydraulic conductivity ($k$) from falling-head and constant-head permeameter tests with water temperature viscosity normalization ($k_{20}$).

Soil Liquefaction Cyclic Stress Ratio Calculator

Geotechnical earthquake engineering: Calculate seismic Cyclic Stress Ratio ($CSR$), SPT-based Cyclic Resistance Ratio ($CRR_{7.5}$), and liquefaction triggering factor of safety ($FS_{liq}$) per Seed-Idriss and Youd et al. (NCEER).

Soil Shear Modulus Gmax Wave Velocity Calculator

Soil dynamics & geotechnical earthquake engineering: Compute small-strain maximum shear modulus ($G_{max} = \rho V_s^2$), Hardin-Black void ratio correlations, and shear strain degradation ($G/G_{max}$).

Solar Array String Sizing MPPT Calculator

Compute minimum and maximum modules per series string to satisfy inverter MPPT voltage limits and NEC 690.7 cold-weather maximum voltage constraints.

Solar Cell Anti-Reflective Coating Calculator

Determine optimal quarter-wavelength coating thickness ($d = \lambda_0 / 4n$), ideal refractive index ($n_{arc} = \sqrt{n_0 n_s}$), and residual spectral reflectance.

Solar Cell Single Diode IV Curve Calculator

Determine open-circuit voltage ($V_{oc}$), short-circuit current ($I_{sc}$), Maximum Power Point ($V_{mp}, I_{mp}, P_{max}$), Fill Factor ($FF$), and parasitic resistance losses.

Solar Panel Temperature Loss Calculator

Determine actual operating cell temperature ($T_{cell}$) from NOCT/NMOT, output power thermal derating, and summer voltage drop.

Solar Radiation Pressure Orbit Drift Calculator

Orbital Perturbations & Space Debris: Model solar radiation pressure (SRP) acceleration ($a_{srp}$), long-period eccentricity oscillations, and perigee pumping for high area-to-mass satellites.

Solar Radiation Pressure Orbit Perturbation Calculator

Orbital Perturbation Dynamics: Compute solar photon radiation force, characteristic perturbation acceleration, orbital eccentricity drift ($de/dt$), and stationkeeping fuel penalty.

Soldier Pile & Lagging Retaining Calculator

Deep excavation & shoring design: Calculate soldier pile maximum bending moment, required steel section modulus ($S_x$), and timber lagging thickness from earth pressure envelopes.

Solid Oxide Ceramic Conductivity Calculator

Electrochemistry & ceramic electrolytes: Calculate oxygen ion conductivity (σ), Arrhenius hopping activation energy, electrolyte thickness, and Area Specific Resistance (ASR).

Solid Rocket Grain Thrust Profile Calculator

Aerospace propulsion & solid rocketry: Model propellant grain burn geometry ($A_b$), web fraction, chamber pressure ($P_c$), and progressive/regressive/neutral thrust curves.

Solid Rocket Motor Burn Rate Calculator

Model propellant linear burn rate (Saint-Robert's Law), Kn area ratio, equilibrium chamber pressure, and combustion stability margins.

Solid Suspension Njs Calculator - Zwietering Agitation

Calculate the minimum just-suspended impeller speed (Njs) to prevent particle settling and filleting using the classic Zwietering correlation.

Solid Suspension Speed Calculator - Zwietering Njs Sizing

Determine minimum impeller rotational speed Njs required to ensure no solid particle remains stationary on the vessel bottom for >1–2 seconds.

Sommerfeld Number Calculator - Journal Bearing Oil Film

Determine dimensionless Sommerfeld number (S), journal eccentricity ratio (ε), and minimum hydrodynamic oil film thickness (h0) per Raimondi-Boyd.

Sonar Equation & Transmission Loss Calculator

Underwater acoustic engineering: Solve active and passive sonar equations, transmission loss (TL), seawater chemical absorption, and acoustic Figure of Merit (FOM).

Space Reactor Shadow Shield Calculator

Nuclear Space Architecture: Model layered heavy-metal (W) gamma and light-element (LiH) fast neutron attenuation, shadow cone geometry, and astronaut crew cumulative dose.

Spacecraft Battery Orbital DoD Calculator

Space Power Subsystems: Size spacecraft battery capacity (Wh & Ah), determine maximum allowable Depth of Discharge (DoD), and calculate orbital cycle life.

Spacecraft Heat Pipe Capillary Calculator

Thermal control & two-phase transport: Calculate Constant Conductance Heat Pipe (CCHP) capillary pumping limit (Q·L_eff), axial groove geometry, and dryout margin.