Starlight Tools

Environment & Sustainability

Free browser-based environment tools to measure and reduce carbon, air quality, energy, water, waste, and renewable impacts. Everything runs locally in your browser for privacy. Try our Carbon Footprint Calculator, AQI to PM2.5 Converter, Solar Energy Calculator, EV vs Gas CO₂ Calculator, Rain Garden Sizing Calculator, or Native Plant Garden Water Savings Calculator.

Environment carbon footprint calculator tool for home energy, travel, diet, and consumption emissions

Carbon Footprint Calculator

Estimate annual CO₂e from home energy, travel, diet, and consumption. Transparent factors. Private, client-side. v1.0.0

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Environment AQI to PM2.5 converter showing air quality category and breakpoint results

AQI to PM2.5 Converter

Convert U.S. AQI to PM2.5, calculate PM2.5 AQI category, and review EPA 2024 breakpoint ranges. Private, client-side. v1.0.0

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Environment flight emissions calculator tool with trip legs, seat class, aircraft preset, and contrail RFI toggle

Flight Emissions Calculator

Estimate per-passenger CO₂ for single or multi-leg trips by distance and seat class. Add passengers, round-trip, aircraft presets, and optional RFI for contrails. v1.0.0

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Environment solar energy calculator tool with latitude, tilt, azimuth, array size and kWh output

Solar Energy Calculator

Estimate kWh/day (plus monthly & yearly) and bill savings from location, tilt, azimuth, and array size. Private, client-side. v1.0.0

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Environment commute emissions calculator comparing CO₂ for car, bus, train, and bike per trip

Commute Emissions Comparison

Compare CO₂ for car, bike, bus, and train. Enter distance and frequency, carpool size, and energy factors. Private, client-side. v1.0.0

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Environment carbon offset estimator tool showing trees planted and renewable kWh needed to balance CO₂

Carbon Offset Estimator

See how many trees or renewable kWh could offset a CO₂ amount. Adjustable growth, buffers, and grid intensity. Private, client-side. v1.0.0

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Environment home energy usage calculator tool with appliance kWh, cost, and CO₂ totals

Home Energy Usage Calculator

Estimate annual kWh, cost, and CO₂ for common appliances. Presets + custom items, standby power, editable tariff & grid. Private, client-side. v1.0.0

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Environment home weatherization savings calculator for insulation, air sealing, drafts, CO2, and payback

Home Weatherization Savings Calculator

Estimate bill savings, CO2 reduction, project net cost, and payback from insulation, air sealing, weatherstripping, and draft fixes. Private, client-side. v1.0.0

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Environment tree shade cooling savings calculator estimating AC bill savings from shade trees

Tree Shade Cooling Savings Calculator

Estimate AC kWh savings, bill savings, CO2 reduction, and payback from shade trees around a home or small building. Private, client-side. v1.0.0

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Environment clothesline versus dryer energy savings calculator showing kWh, cost, CO2, and payback

Clothesline vs Dryer Energy Savings Calculator

Estimate kWh, therms, bill savings, CO2 reduction, dryer cycles avoided, and clothesline payback from line drying laundry. Private, client-side. v1.0.0

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Environment heating comparison calculator for heat pump, electric resistance, and gas boiler efficiency

Electricity vs. Gas Heating

Compare heat pump, electric resistance, and gas boiler on energy in, cost, and CO₂. Editable COP, prices, and factors. Private, client-side. v1.0.0

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Environment EV vs gas car CO₂ calculator comparing grid intensity, fuel factors, and battery manufacturing

EV vs. Gas Car CO₂ Calculator

Estimate per-km and lifetime emissions with editable grid intensity, fuel factors, and battery assumptions. v1.0.0

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Environment reusable cup impact calculator comparing disposable cups avoided and annual CO₂ savings

Reusable Cup Impact Calculator

Estimate cups avoided and CO₂ saved per year from reusable cups vs single-use. Friendly, editable, client-side. v1.0.0

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Environment reusable bag impact calculator showing plastic bags avoided and CO2e saved

Reusable Bag Impact Calculator

Estimate plastic bags avoided, plastic waste avoided, and net CO2e saved from reusable shopping bags. Editable, private, client-side. v1.0.0

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Environment wind turbine output calculator showing rotor diameter, wind speed, and power curve outputs

Wind Turbine Output Calculator

Estimate power from wind speed & rotor diameter, with Cp, efficiency, and cut-in/out. Get daily & annual kWh via capacity factor or hours/day. v1.0.0

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Environment ocean plastic decomposition timeline showing plastic types and marine breakdown

Ocean Plastic Decomposition Timer

Interactive timeline of estimated fragmentation/decomposition times for common plastics by marine environment. Private, client-side. v1.0.0

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Environment battery storage sizing calculator for daily load, autonomy days, depth of discharge, and module count

Battery Storage Sizing Tool

Estimate usable & nameplate kWh from daily load, autonomy days, DoD, and efficiencies. Includes module count and power/current checks. v1.0.0

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Environment reforestation impact estimator chart of tree planting CO₂ sequestration over years

Reforestation Impact Estimator

Estimate total CO₂ sequestered by planted trees over time. Editable growth, survival, and buffer. Private, client-side. v1.0.0

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Environment water footprint calculator cards for household taps, showers, laundry, and diet water use

Water Footprint Calculator

Estimate daily or annual water use from showers, laundry, taps/toilets, dishwasher, outdoor watering, and diet. Private, client-side. v1.0.0

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Environment greywater reuse estimator showing capture sources, storage tank, and toilet irrigation reuse

Greywater Reuse Estimator

Estimate mains water & bill savings by reusing shower/sink/laundry water for toilets and irrigation. Editable capture, storage, tariffs. Private, client-side. v1.0.0

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Environment plastic footprint calculator with category cards for bottles, bags, packaging and optional CO₂e

Plastic Footprint Calculator

Estimate yearly bottles, bags, and packaging — pieces, mass, and optional CO₂e. Edit weights, reuse, and recycling. Private, client-side. v1.0.0

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Environment paper vs digital impact calculator estimating trees, water, and energy saved when pages go digital

Paper vs. Digital Impact

Estimate trees, water, and energy saved when pages go digital. Editable factors, private, client-side. v1.0.0

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Environment shower water and energy calculator inputs for flow rate, minutes, temperature, cost, and CO₂

Shower Water & Energy Calculator

Estimate shower litres, kWh to heat, cost, and CO₂—gentle defaults, fully editable. Private, 100% client-side. v1.0.0

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Environment heat pump water heater savings calculator comparing annual cost, CO2, and payback

Heat Pump Water Heater Savings Calculator

Estimate bill savings, CO2 reduction, incentives, and payback when switching from electric or gas water heating to a heat pump water heater. Private, client-side. v1.0.0

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Environment waste reduction impact calculator comparing landfill versus recycling CO₂ savings bars

Waste Reduction Impact

Estimate CO₂e saved by recycling versus landfill or incineration. Editable factors, per-kg view, and private, 100% client-side. v1.0.0

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Environment e-waste recycling impact calculator showing electronics diversion and CO2e estimate

E-Waste Recycling Impact Calculator

Estimate electronics reuse, recycling, landfill diversion, screening CO2e benefit, phone metals recovered, and laptop energy-equivalent savings. Private, client-side. v1.0.0

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Environment food waste landfill methane calculator showing landfill methane and CO2e estimate bars

Food Waste Landfill Methane Calculator

Estimate CH4 and CO2e from food waste sent to landfill with editable IPCC-style factors, methane recovery, oxidation, and diversion targets. Private, client-side. v1.0.0

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Environment composting impact calculator showing food scraps, yard waste, and CO2e savings

Composting Impact Calculator

Estimate CO2e saved by composting food scraps and yard waste instead of landfill disposal. Editable landfill, compost CH4, N2O, and GWP assumptions. Private, client-side. v1.0.0

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Environment solar payback calculator charting costs, incentives, yearly cash flow, and breakeven point

Solar Payback Calculator

Estimate time to break even, year-by-year cash flow, NPV & IRR from cost, incentives, kWh, and tariffs. Private, client-side.

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Environment LED vs incandescent savings calculator showing bulb wattage, hours, and annual kWh

LED vs. Incandescent Savings

Estimate annual kWh, bill savings, and optional payback from switching to LEDs. Private, client-side.

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Environment rainwater harvesting calculator with roof size, rainfall, runoff coefficient, and tank sizing

Rainwater Harvesting Calculator

Estimate potential collection from roof size and rainfall with annual or monthly inputs, runoff coefficient, filter efficiency, first-flush, and optional tank sizing. Private, client-side. v1.0.0

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Environment rain garden sizing calculator for stormwater runoff area, ponding depth, and infiltration

Rain Garden Sizing Calculator

Size a residential rain garden from drainage area, design storm depth, runoff coefficient, ponding depth, infiltration rate, and safety factor. Private, client-side. v1.0.0

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Environment native plant garden water savings calculator comparing lawn irrigation to mature native planting water needs

Native Plant Garden Water Savings Calculator

Estimate water and bill savings from replacing lawn or high-water beds with native, regionally appropriate plants. Establishment and mature-year views. Private, client-side. v1.0.0

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Environment permeable pavement runoff reduction calculator for stormwater storage, infiltration, overflow, and drawdown

Permeable Pavement Runoff Reduction Calculator

Estimate runoff avoided, overflow, storage use, drawdown time, and annualized stormwater reduction for porous asphalt, pervious concrete, or permeable pavers. Private, client-side. v1.0.0

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Environment urban heat reduction calculator estimating cooling from tree canopy, shade, green roofs, and cool paving

Urban Heat Reduction Calculator

Estimate local cooling from added tree canopy, shade, green roofs, and higher-albedo paving. Friendly defaults, editable coefficients, private & client-side. v1.0.0

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About These Environment & Sustainability Tools

Starlight Tools provides privacy-first calculators to track carbon, air quality, energy, water, waste, and renewable projects without uploading any data. Every calculation runs in your browser so your environmental data stays on your device.

Popular picks include the Carbon Footprint Calculator, AQI to PM2.5 Converter, Solar Energy Calculator, EV vs Gas CO₂ Calculator, and Water Footprint Calculator. Use them anytime to plan greener choices.