Science & Weather Tools
Electricity, weather, psychrometrics (wet bulb / dew point / heat index), cooling towers, AQI, and a simple carbon footprint.
Ohm's Law Solver
Solve Ohm's law for voltage, current, or resistance using V = I * R.
Resistor Network Calculator (Series/Parallel)
Compute equivalent resistance for two resistors in series or parallel.
Voltage Drop Estimator
Estimate voltage drop using a simplified Vdrop = I * (R_per_unit * length) model.
Wind Chill Calculator
Estimate wind chill (F and C) from temperature and wind speed.
Parked Vehicle Temperature Calculator
Estimate parked vehicle cabin temperature rise over time using Newton heating with solar gain, paint absorption, ventilation, and wind cooling.
Heat Index Calculator
Estimate heat index from temperature and relative humidity.
Dew Point Calculator
Estimate dew point from temperature and relative humidity.
Wet Bulb / Dry Bulb & Psychrometrics
From temperature and humidity: wet bulb (Stull 2011), dew point (Magnus), and heat index in one view for HVAC, towers, and weather.
Cooling Tower Efficiency Calculator
Compute thermal range, approach to wet bulb, and tower effectiveness from hot water, cold water, and entering air wet-bulb temperature.
AQI Calculator (PM2.5, PM10, NO₂, O₃)
Estimate US AQI sub-indices from pollutant concentrations and overall AQI as the max; optional illustrative city presets.
Carbon Footprint Calculator
Estimate annual CO2e from car, flights, home electricity (grid presets), diet baseline, and monthly lifestyle extras, plus rough tree equivalents.
Digital Carbon Footprint Calculator
Estimate CO₂ from gigabytes transferred (0.06 kg CO₂ per GB) and compare to minutes of typical hair-dryer electricity.
LED vs Incandescent ROI Calculator
Compute yearly electricity savings from wattage swap, hours, and tariff; break-even months = bulb cost ÷ monthly savings.
Flight Emissions (Short vs Long Haul)
Estimate illustrative kg CO₂ as distance × factor: 0.25 kg/km under 1500 km, 0.15 above 3700 km, blended mid-haul.
Drip Leak Water Waste Calculator
Liters wasted per day = drops per minute × 0.2; compare to standard 20 L water cooler jugs.
Virtual Water Footprint Calculator
Total water = quantity × intensity: beef, chocolate, coffee (L/kg) and cotton shirt (L per shirt) with sliders.
Shower vs Bath Water Calculator
Compare a 150 L bath to shower minutes at 9.5 L/min; see when a long shower exceeds the tub.
Decomposition Timeline Lookup
Searchable persistence table with a bar chart vs ~80 year human life expectancy.
Compost Methane Avoidance Calculator
CO₂ equivalent saved ≈ kg of food waste diverted × 0.5 (landfill methane proxy).
Cost Per Wear Calculator (Fashion)
Price per wear = (purchase + maintenance) ÷ wears; sliders compare to a disposable price benchmark.
Food Miles Tracker
Transport impact score = weight × distance × mode factor (air 1.13, truck 0.2, train 0.03) with sliders.
Energy Density Comparator
Compare gravimetric energy density (Wh/kg) for batteries, diesel, petrol, coal, natural gas, and hydrogen. Sliders for mass, optional efficiency override, Chart.js bars, CO₂ and cost hints, and home/EV equivalents.
Lighting Throw Distance (Lux)
Estimate on-axis illuminance in lux from fixture lumens, full beam angle, and distance for home studio and video lighting planning.
18650 Battery Pack Configurator
Compute nominal pack voltage, total mAh, and Wh for custom S×P 18650 layouts with adjustable nominal cell voltage and cell capacity.
Thermal Expansion Gap Calculator
Estimate linear expansion or contraction from ΔT and length for aluminum, steel, and generic polymer α values—useful for mounts, panels, and car interior swings.
Half-Life Decay Calculator
Compute remaining fraction after time t given half-life.
Molarity & Dilution Calculator
Moles per litre and dilution helper.
pH Calculator
pH from [H+] or buffer ratio with pKa.
Reaction Yield Calculator
Calculate percentage yield from actual product and theoretical yield.
Normality (N) from Molarity
Convert molarity (mol/L) to normality (eq/L) using the active n-factor.
Dilution Calculator (M₁V₁ = M₂V₂)
Solve missing concentration or volume in a dilution (ideal solution, same units).