Engineering & Science calculators
Choose a task below. Check each calculator’s assumptions and units before using its result.
Prosthetic Running Blade Spring Calculator
Prosthetic biomechanics & athletic engineering: Determine carbon fiber running blade dynamic stiffness ($k$), elastic strain energy return ($U$), and natural cadence resonance.
PRV Backpressure Derating Calculator - API 520 Bellows Kw
Determine PRV backpressure capacity derating factors Kw and Kb, built-up vs superimposed limits, and valve type selection (Conventional, Balanced Bellows, or Pilot-Operated) per API 520.
PRV Inlet Pressure Loss Calculator - API 520 3 Percent Rule
Calculate total non-recoverable frictional pressure loss between vessel nozzle and PRV inlet flange to prevent destructive valve chattering per API 520 Part II.
PSV Reaction Force Calculator - API 520 Tailpipe Thrust
Calculate steady-state momentum reaction force, sonic pressure thrust, and dynamic load factor (DLF) for open-ended atmospheric relief valve tailpipes per API 520 Part II.
Psychrometric SHR Apparatus Dew Point Calculator
HVAC Air Conditioning Thermodynamics: Calculate Sensible Heat Ratio ($SHR$), Apparatus Dew Point ($T_{adp}$), coil bypass factor ($BF$), and required airflow ($CFM$).
Pulp Freeness CSF & SR Calculator
Mechanical refining kinetics: Convert between Canadian Standard Freeness (CSF) and Schopper-Riegler (°SR), calculate Specific Refining Energy (SRE), and track strength.
Pulsation Dampener Sizing Calculator - API 618 Bottle Vol
Size suction and discharge pulsation dampener bottles and internal choke tubes per API 618 Design Approach 1 & 2 to suppress acoustic pressure pulsations and pipe vibration.
Pulse Doppler Radar Range Calculator
Coherent radar signal processing: Analyze the PRF compromise between maximum unambiguous range (R_ua), Doppler blind speed (v_blind), and average transmitter power.
Pulse Jet Baghouse Calculator - Cleaning Air CFM Demand
Determine continuous compressed air supply demand (SCFM), free air volume per pulse, manifold header surge tank volume, and air compressor horsepower.
Pulse Tube Cryocooler Acoustic COP Calculator
Cryogenic Refrigeration: Calculate time-averaged acoustic work flow ($\langle P\dot{V}\rangle$), phase shift angle ($\theta_{PV}$), cryogenic cooling capacity, and percent of Carnot COP.
Pulsed Plasma Thruster Impulse Bit Calculator
CubeSat & SmallSat Micro-Propulsion: Calculate capacitor bank discharge energy ($E_0$), impulse bit ($I_{bit}$), specific impulse ($I_{sp}$), and average thrust.
Pump Minimum Flow Calculator - MCSF Thermal Limit Sizing
Calculate Minimum Continuous Stable Flow (MCSF), Minimum Continuous Thermal Flow (MCTF), low-flow fluid temperature rise, and bypass protection orifice sizing per API 610 and ANSI/HI 9.6.3.
Pumped Storage Hydro Efficiency Calculator
Hydropower & Energy Storage: Compute round-trip efficiency (RTE), cycle energy losses, water volume, and generation capacity.
PWR Pressurizer Surge Line Stratification Calculator
Compute top-to-bottom temperature gradient (ΔT), thermal bowing curvature, bending stress, and cumulative fatigue usage factor per NRC Bulletin 88-11.
Quantum Well Energy Eigenstates Calculator
Quantum mechanics & semiconductor lasers: Solve 1D particle-in-a-box energy confinement states ($E_{e,n}, E_{hh,n}$), effective bandgap blue-shift, and emission wavelength ($\lambda$).
Quarter-Wave Bragg Mirror Reflectivity Calculator
Laser Thin-Film Optics: Compute multi-layer dielectric high-reflector ($HR$) reflectivity, transmission loss ($1-R$ in ppm), stopband reflection bandwidth, and layer thicknesses.
Qubit Purcell Effect Decay Rate Calculator
Circuit Quantum Electrodynamics (cQED): Calculate spontaneous emission decay into readout transmission lines ($\gamma_P$), Purcell-limited relaxation lifetime ($T_{1,P}$), and Purcell filter suppression factor.
Radar Cross Section RCS Calculator
Electromagnetic Scattering: Calculate geometric optics RCS ($\sigma$) in $\text{m}^2$ and $\text{dBsm}$ across canonical radar reflector geometries.
Radar Cross-Section RCS Calculator
Electromagnetic scattering: Calculate monostatic radar cross-section (RCS) in m² and dBsm for canonical geometries: flat plates, spheres, cylinders, and trihedral reflectors.
Radar Horizon & Ducting Calculator
Radio wave propagation: Calculate geometric & 4/3 refracted radar horizons, sea-skimmer detection ranges, and atmospheric ducting trapping frequencies.
Radar Pulse Compression Ambiguity Calculator
Radar Waveform Engineering: Compute Linear Frequency Modulation (LFM) chirp pulse compression ratio, range resolution ($\Delta R$), and range-Doppler cross-coupling errors.
Radar Range Equation Calculator
Radar system electromagnetics: Solve the classic radar range equation for maximum detection range (R_max), received power (P_r), and signal-to-noise ratio (SNR).
Radar Range Equation SNR Calculator
Radar Systems: Calculate received echo power ($P_r$), Signal-to-Noise Ratio (SNR), thermal noise floor, and maximum detection range ($R_{max}$).
Radar Search Volume Frame Time Calculator
Surveillance Radar Scheduling: Calculate spatial search coverage, number of beam positions, dwell times, and total volume frame refresh rates for AESA and mechanically scanned radars.
Radar Target RCS Detection Range Calculator
Radar Systems & Sensor Physics: Compute maximum free-space detection range ($R_{\text{max}}$) for targets across conventional and stealth Radar Cross Section (RCS) categories.
Radial Flow Darcy Skin Factor Calculator
Determine steady-state oil production rate ($q$), Hawkins near-wellbore skin factor ($s$), additional drawdown loss ($\Delta p_s$), and Flow Efficiency ($FE$).
Radiated Emissions Loop Antenna Calculator
EMC Regulatory Compliance: Predict radiated electric field strength ($E$), compare against FCC Part 15 and CISPR 32 limits, and determine maximum allowable loop area.
Radioisotope Generator RTG Decay Calculator
Deep-Space Power Engineering: Predict Plutonium-238 thermal decay ($Q_{\text{th}}$), thermocouple degradation, and net electrical power ($P_e$) over decades.
Railway Ballast Settlement Decay Calculator
Track Maintenance Engineering: Predict permanent ballast settlement vs cumulative traffic (MGT), Track Quality Index (TQI) degradation, and optimal mechanized tamping intervals.
Railway Cant Superelevation Calculator - AREMA Speed Sizing
Calculate railway track equilibrium cant, cant deficiency, maximum permissible passenger speed, and uncompensated lateral acceleration per AREMA & EN 14363.
Railway Curve Superelevation Calculator
Railway civil design & track geometry: Calculate equilibrium superelevation (cant $E_a$), cant deficiency ($D$), uncompensated lateral centrifugal acceleration, and minimum spiral transition length.
Railway Hunting Critical Speed Calculator
Railway vehicle dynamics & bogie stability: Calculate Klingel's kinematic hunting wavelength ($\lambda$), oscillation frequency ($f_h$), effective conicity ($\gamma_{eff}$), and dynamic critical hunting speed ($V_{crit}$).
Railway Track Cant & Curving Speed Calculator
Compute curve superelevation, equilibrium cant ($E_{eq}$), cant deficiency ($D$), unbalanced lateral acceleration, and maximum safe curving speed.
Railway Transition Spiral Calculator - AREMA Jerk Sizing
Calculate minimum transition spiral length, rate of cant elevation, rate of cant deficiency change, passenger lateral jerk, and curve shift per AREMA & UIC 703.
Railway Turnout & Crossing Geometry Calculator
Compute turnout closure curve radius ($R$), lead length ($L$), crossing frog angle ($\theta$), and maximum diverging branching speed.
Rapid Thermal Annealing Dopant Calculator
Semiconductor Junction Engineering: Compute effective thermal budget (Dt), dopant electrical activation fraction, junction depth displacement (Δx_j), and sheet resistance.
Rayleigh Photolithography Resolution Calculator
Semiconductor microelectronics & advanced patterning: Compute critical dimension (CD) resolution, depth of focus (DOF), and process window across DUV, ArFi, and EUV lithography systems.
Rayleigh-Taylor Instability Growth Rate Calculator
Hydrodynamic stability & interfacial fluid dynamics: Calculate the Atwood number ($A$), linear Rayleigh-Taylor growth rate ($\gamma$), surface tension cutoff wavelength ($\lambda_c$), and non-linear bubble/spike velocities.
Reaction Injection Molding RIM Calculator
Polyurethane & thermoset composites: Calculate high-pressure impingement mixing nozzle Reynolds numbers, mixhead pressure drop, and mold filling time vs cream time.
Reactive Ion Etching ARDE Microloading Calculator
Microfabrication & plasma etching: Model Aspect Ratio Dependent Etching (ARDE / RIE lag), Knudsen radical transport down deep trenches, mask selectivity erosion, and total process etch time ($t_{etch}$).
Reactor Coolant Channel Enthalpy Rise Calculator
Core Thermal-Hydraulics: Model subchannel coolant enthalpy rise $\Delta h(z)$, axial chopped cosine flux distribution, and bulk water temperature across active core height.
Reactor Decay Heat ANS 5.1 Standard Calculator
Determine post-trip thermal power decay fraction P(t)/P_0 from 1 second to 30 days following scram using ANSI/ANS-5.1-2014 standards.
Reactor Four-Factor Multiplication Calculator
Nuclear reactor physics: Compute k_inf via the four-factor formula (ε, p, η, f), fast/thermal non-leakage probabilities, geometric buckling, and k_eff.
Reactor Inhour & Reactivity Period Calculator
Nuclear kinetics: Solve the 6-group precursor Inhour equation relating reactivity insertion (ρ, $) to stable reactor period (T) and power doubling time.
Reactor Inhour Equation & Kinetics Calculator
Calculate reactor asymptotic period ($T$), reactivity in dollars and pcm, prompt jump amplitude, and delayed neutron precursor kinetics via the Inhour equation.
Reactor Point Kinetics Inhour Calculator
Calculate reactor reactivity ($\rho$ in pcm and $\$), asymptotic stable reactor period ($T$), prompt jump power ratio, and delayed neutron precursor decay.
Reactor Xenon Poisoning & Iodine Pit Calculator
Reactor operational physics: Model steady-state Xe-135 poisoning, post-scram Iodine Pit transient, peak negative reactivity depth, and restart dead time.
Reactor Xenon Poisoning Iodine Pit Calculator
Nuclear reactor safety & operational physics: Model post-shutdown Xenon-135 peak buildup from Iodine-135 beta decay ("Iodine pit"), negative reactivity insertion ($\Delta\rho_{\text{Xe}}$ in pcm), and reactor deadtime.