Engineering & Science calculators
Choose a task below. Check each calculator’s assumptions and units before using its result.
MOSFET BTI Threshold Aging Calculator
Advanced CMOS Reliability: Model Negative/Positive Bias Temperature Instability (NBTI/PBTI) threshold voltage degradation (ΔV_th) over time, temperature, and gate electric field.
MOSFET Subthreshold Swing & DIBL Calculator
Nanoelectronics & semiconductor device physics: Compute subthreshold swing ($SS$), body ideality factor ($m$), Drain-Induced Barrier Lowering ($DIBL$), and standby off-state leakage current ($I_{off}$).
MPD Thruster Maecker Formula Calculator
High-Power Plasma Propulsion: Calculate self-field Lorentz electromagnetic thrust ($T_{EM}$), gasdynamic thrust, critical onset current, and electrical power.
MSE Wall Geogrid Reinforcement Calculator
Retaining structures & geosynthetics: Design Mechanically Stabilized Earth ($MSE$) walls, geogrid layer tensile loads ($T_{max}$), pullout resistance, and AASHTO embedment lengths.
MSMPR Crystallizer Size Distribution Calculator
Chemical process engineering: Solve the steady-state MSMPR population balance equation ($n(L) = n_0 e^{-L / G\tau}$), calculating nucleation rate ($B_0$), mean residence time ($\tau$), and dominant crystal size ($L_D$).
Mud Acid Stoichiometry Calculator - Sandstone HF HCl
Calculate stoichiometric consumption of hydrofluoric (HF) and hydrochloric (HCl) acid blends for quartz, feldspar, and clay dissolution in sandstone reservoirs.
Multi-Layer Insulation MLI Calculator
Cryogenics & Spacecraft Insulation: Compute radiative heat flux through $N$ radiation shields, effective emittance ($\epsilon^*$), and total parasitic heat leak.
Multibeam Sonar Swath Bathymetry Calculator
Hydrographic surveying & seafloor mapping: Calculate total swath coverage width ($W$), across-track and along-track acoustic footprint sizes, sounding density ($ ext{soundings/m}^2$), and daily survey area rate.
Multibeam Sonar Swath Footprint Calculator
Hydrographic surveying & marine geophysics: Compute swath coverage width, along-track and across-track footprint dimensions, sounding density, and travel time.
Multimode Fiber Modal Dispersion Calculator
Premises networking & data center optics: Compute multimode fiber (MMF) modal dispersion delay spread, parabolic graded-index (GRIN) optimization, and OM1–OM5 bandwidth-distance limits.
Multistage Peltier Cascade Cooler Calculator
Cryogenic Thermoelectrics: Model multi-stage pyramidal cascades (2 to 4 stages) to reach deep sub-zero temperatures (down to -80°C) for optical sensor cooling.
Multistage Rocket Delta-V Calculator
Launch vehicle trajectory design: Calculate cumulative velocity increment across 1 to 3 stages using the Tsiolkovsky rocket equation with gravity and atmospheric losses.
Multistage Rocket Optimal Mass Staging Calculator
Launch Vehicle Sizing: Optimize propellant mass distribution, stage payload ratios, and structural fractions across 2-stage and 3-stage launch vehicles for target mission $\Delta v$.
Natural Ventilation Pressure Mine Calculator
Compute Natural Ventilation Pressure ($NVP$), motive column of air, downcast vs. upcast density gradients, and seasonal thermal draft effects in deep mines.
Negative Index Metamaterial Optics Calculator
Transformation optics & Veselago superlens mechanics: Calculate negative Snell's law refraction ($\theta_t$), flat slab focus coordinates ($d_1 + d_2 = d$), wave impedance ($\eta$), and sub-diffraction super-resolution.
Neutral Beam Plasma Attenuation Calculator
Auxiliary Plasma Heating: Calculate neutral beam ionization cross-section ($\sigma_{eff}$), plasma optical depth ($\tau$), shine-through first-wall heat load, and deposition profile.
Newmark Sliding Block Slope Displacement Calculator
Seismic slope stability & dam engineering: Calculate the critical yield acceleration ($k_y$), critical acceleration ratio ($k_y / a_{max}$), and permanent earthquake sliding displacement ($D_N$) using the Newmark rigid block method.
Newmark-Hall Earthquake Response Spectrum Calculator
Structural earthquake engineering: Construct the tripartite Newmark-Hall elastic design response spectrum, calculating spectral pseudo-acceleration ($S_a$), pseudo-velocity ($S_v$), and relative displacement ($S_d$) at structural period ($T$).
NFPA 68 Dust Explosion Vent Area Calculator
Industrial deflagration venting & process safety: Size explosion relief rupture panels ($A_v$) for dust collectors, silos, and spray dryers per the standard NFPA 68 equations.
NFPA 68 Explosion Vent Calculator - Pred Vent Area Sizing
Calculate combustible dust explosion relief vent area (Av), enclosure reduced pressure (Pred), reaction thrust force, and external fireball length per NFPA 68.
NFPA 69 Inerting LOC Calculator - Oxygen Limit Sizing
Calculate NFPA 69 Limiting Oxygen Concentration (LOC), Maximum Allowable Oxygen Concentration (MOC), temperature derating, and nitrogen purge volume.
Nodal Analysis Calculator - Wellbore Operating Point Sizing
Determine equilibrium well flow rate (q_op) and bottomhole flowing pressure (Pwf_op) by solving the intersection of Inflow and Outflow (VLP) curves.
Noise Criterion NC & Room Criteria Calculator
HVAC acoustics & mechanical noise control: Evaluate octave band sound pressure levels against Noise Criterion ($NC$) and Room Criteria ($RC$) standards per ANSI/ASA S12.2.
Nolte-Smith Net Pressure Calculator - Frac Diagnostics
Interpret real-time log-log net pressure slopes (Mode I to Mode IV) during pumping to diagnose unrestricted propagation, height growth, or impending screenout.
Non-Evaporable Getter Pumping Calculator
Ultra-high & extreme-high vacuum (UHV/XHV): Calculate Non-Evaporable Getter (NEG) initial pumping speed ($S_0$), molecular sticking probability ($\alpha$), hydrogen sorption capacity, and lifetime.
Nuclear Doppler Fuel Coefficient Calculator
Nuclear reactor safety physics: Calculate the prompt Doppler fuel temperature coefficient of reactivity ($\alpha_D = d\rho / dT_{\text{fuel}}$ in $\text{pcm/K}$), U-238 resonance capture broadening, and inherent self-limiting thermal safety.
Nuclear Electric Propulsion Radiator Calculator
Deep Space Power Systems: Calculate closed Brayton cycle thermal efficiency, optimum radiator heat rejection temperature ($T_{rad} \approx 0.75 T_{peak}$), radiator area, and specific mass ($\alpha$).
Nuclear Four-Factor Formula & k-eff Calculator
Calculate infinite multiplication factor ($k_\infty$), reproduction factor ($\eta$), resonance escape ($p$), thermal utilization ($f$), and effective core criticality ($k_{eff}$).
Nuclear Fuel Burnup & Depletion Calculator
Nuclear fuel cycle engineering: Calculate fuel burnup ($B$ in $\text{GWd/tU}$ and $\text{MWd/kgHM}$), Fissions per Initial Metal Atom ($\text{FIMA}\%$), U-235 isotopic consumption, and fission product mass.
Nuclear Fuel Burnup & U-235 Depletion Calculator
Calculate cumulative fuel assembly discharge burnup (GWd/tU), initial and final U-235 enrichment, Pu-239 breeding conversion ratio, and isotopic consumption.
Nuclear Fuel Pin Radial Temperature Calculator
Fuel Rod Performance: Compute radial temperature gradients across $\text{UO}_2$ ceramic pellets, helium gas gap, and Zircaloy cladding to determine centerline melting margins.
Nuclear Reactor ANS 5.1 Decay Heat Calculator
Reactor Safety & Thermal Hydraulics: Compute post-shutdown radioactive decay heat power ($P_d$), Way-Wigner approximations, ANS 5.1 multi-group models, and emergency cooling flow rates.
Nuclear Reactor Inhour Reactivity Calculator
Nuclear reactor kinetics & control: Solve the 6-group delayed neutron Inhour equation relating reactivity ($\rho$, in $\text{pcm}$ and dollars $\$), stable asymptotic reactor period ($T$), and prompt neutron generation time ($\Lambda$).
Nuclear Rocket Core Heat Transfer Calculator
Reactor Thermal Hydraulics: Calculate hydrogen forced-convective heat transfer coefficients, variable-property Nusselt corrections, core pressure drop, and peak fuel centerline temperature.
Nuclear Rocket Turbopump Cycle Calculator
NTP Engine Systems Engineering: Model turbopump shaft power balance, closed expander vs hot bleed cycle thermodynamics, and net specific impulse efficiency.
Nuclear Thermal Rocket Isp Calculator
Space Nuclear Propulsion: Calculate specific impulse ($I_{sp}$), molecular hydrogen thermal dissociation, characteristic velocity ($c^*$), and vacuum thrust per unit flow rate.
Oberth Effect Hyperbolic Burn Calculator
Interplanetary Astrodynamics: Quantify the Oberth effect kinetic energy amplification, hyperbolic excess speed ($V_\infty$), and velocity magnification for periapsis rocket burns.
Offshore Monopile Wave Force Calculator
Offshore Engineering: Calculate hydrodynamic drag ($F_D$), inertia ($F_M$), and maximum seabed overturning moment ($M_{base}$) via Morison equation.
Offshore Platform Wave Air Gap Calculator
MetOcean & Structural Safety: Calculate net air gap clearance under 100-year extreme crest elevation ($\eta_{max}$), storm surge, and wave run-up.
Offshore Turbine Frequency Calculator
Structural Dynamics: Calculate combined tower-monopile first natural frequency ($f_0$) and verify Campbell diagram "soft-stiff" margins between $1P$ and $3P$.
Offshore Wind Monopile Calculator - 1P 3P Resonance DNV
Calculate monopile fundamental natural frequency, 1P mass imbalance and 3P blade passing frequency exclusion bands, and DNV-ST-0126 dynamic resonance margins.
Oil Whirl & Whip Threshold Calculator - Bearing Stability
Estimate rotordynamic oil whirl onset speed, whirl frequency ratio (WFR), and critical threshold velocity to avoid destructive subharmonic instability.
One-Compartment Pharmacokinetics Calculator
Determine elimination rate constant ($k_e$), biological half-life ($t_{1/2}$), apparent volume of distribution ($V_d$), total body clearance ($CL$), and steady-state concentration ($C_{ss}$).
Open Pit Blast Powder Factor Calculator
Drilling & blasting engineering: Calculate burden, spacing, subdrill, explosive mass per blast hole, and powder factor in kg/m³ and kg/tonne.
Optical Fiber Chromatic Dispersion Calculator
Optical telecommunications & photonics: Calculate chromatic dispersion parameter ($D$), group velocity dispersion ($\beta_2$), pulse temporal broadening ($\Delta \tau$), and dispersion-limited transmission distance & bit rate.
Optical Fiber NA & V-Number Mode Calculator
Determine fiber Numerical Aperture (NA), acceptance cone angle, normalized frequency (V-number), single-mode cutoff condition, and guided LP mode capacity.
Optical Link OSNR Budget and BER Calculator
DWDM Telecom Network Design: Calculate cascaded EDFA optical signal-to-noise ratio ($OSNR_{0.1nm}$), linear Q-factor, and Pre-FEC Bit Error Rate ($BER$).
Optical Proximity Correction OPC Calculator
Computational lithography & photomask synthesis: Model line-end pullback (foreshortening), iso-dense proximity bias, corner rounding, and serif compensation geometry.