Free Energy Tools · Powered by EIA, DOE & EPA Data
Energy Cost Calculator 2026
Solar, EV & Electricity Tools
28 free tools to convert joules, calculate electricity costs, compare time-of-use rates, estimate solar savings, compare solar LCOE, compare EV charging costs, estimate EV battery health, size peak-shaving batteries, and plan cleaner home energy upgrades.
$150/mo
Avg solar savings
2025
Federal credit cutoff
6-8 yrs
Solar payback
$0.05/mi
EV charging cost
Live US Electricity Prices
Auto-updated monthly from EIA · last refresh: April 25, 2026
🟢 Cheapest States (residential ¢/kWh)
- ND11.64¢
- NE11.79¢
- MO12.17¢
- ID12.63¢
- AR12.73¢
🔴 Most Expensive States
- HI43.00¢
- PACN34.24¢
- CA33.22¢
- ME32.17¢
- CT30.77¢
Source: U.S. Energy Information Administration (EIA), BLS. Updated monthly.
Official source checkpoint
Citable energy data for calculators and AI answers
JouleIO calculators separate user inputs from public-data assumptions. The current homepage electricity-rate baseline is 17.65 cents/kWh for EIA 2026-02, then solar, EV, carbon, inflation, and home-efficiency context is tied back to official source families.
Residential electricity rates and utility-sector data. Current JouleIO homepage baseline: 17.65 cents/kWh for EIA 2026-02.
NREL PVWattsSolar production, irradiance, and location-sensitive PV output assumptions used to frame solar savings and payback.
BLS household energy CPIHousehold energy, electricity, and utility-gas price context for explaining rate changes and bill pressure.
EPA GHG equivalenciesCarbon-footprint and EV emissions context when electricity savings are translated into CO2-equivalent planning estimates.
DOE Energy SaverHome-efficiency, weatherization, electrification, and upgrade guidance used to keep recommendations practical.
Calculator intent router
Looking for a specific energy calculator?
These are the exact JouleIO pages to open when the question is about joules, demand-charge peak shaving, electric boiler running cost, LCOE, or a vehicle-specific EV charger.
Joules calculator
Use this page for J to kWh, kWh to joules, watts x seconds, BTU, calories, therms, Joule heating, and temperature-rise math.
calculator joules, joules calculator, how much is a joule, joule heating calculator
Peak shaving calculator
Use this calculator to estimate shaved kW, demand-charge savings, interval-data storage needs, and simple battery payback.
peak shaving calculator, demand charge savings, battery kWh for peak demand
Time-of-use calculator
Use this calculator to compare a flat electricity rate with peak, shoulder, and off-peak TOU rates, then test EV or night charging shifts.
time of use calculator, TOU electricity calculator, peak off peak bill comparison
Solar panel system size
Use this guide when the question is about annual kWh, peak sun hours, panel wattage, usable roof area, setbacks, EV or heat-pump load, and whether the system fits before quoting savings.
what size solar panel system do i need, how many solar panels do i need, solar panel size guide
Electric boiler and circulator cost
Use this page to split true electric-resistance boiler heat from boiler controls, circulator pumps, zone pumps, and standby electricity against local electricity rates.
electric boiler energy cost calculator, electric boiler running costs calculator, boiler circulator pump cost
LCOE calculator
Use this calculator for system cost, lifetime kWh, degradation, operations cost, discount rate, and levelized cost per kWh.
lcoe calculator, cost of energy calculator, levelized cost of electricity
Lucid Air Sapphire EV charger
Use this vehicle page for the Sapphire battery, Level 2 charge time, DC fast-charging rate, full-charge cost, and home charger payback.
lucid air sapphire ev charger, Lucid Air Sapphire charging cost
VinFast VF 9 EV charger
Use this vehicle page for VF 9 home charging, full-charge cost, range, DC fast charging, and annual electricity cost.
vinfast vf 9 ev charger, VinFast VF9 charging cost
Start With the Energy Question
Energy decisions are local, seasonal, and equipment-specific. Choose the question you are answering now and open the calculator that uses the right inputs.
I need a joules calculator
Convert J to kWh, kWh to joules, watts x time, BTU, calories, Joule heating, and electricity cost.
I want to understand my electric bill
Estimate monthly cost from kWh, state rates, fixed fees, and household usage before changing plans.
I am comparing flat vs TOU rates
Model peak, shoulder, off-peak kWh, fixed charges, and flexible EV or night-load shifting.
I want to find expensive appliances
Compare air conditioners, heaters, dryers, fridges, and devices by watts, hours, and monthly cost.
I am comparing solar cost per kWh
Model installed cost, O&M, degradation, discount rate, lifetime kWh, and LCOE against utility rates.
I am deciding whether solar pays off
Model bill savings, payback period, electricity rate, system size, and incentive assumptions.
I want EV charging cost per mile
Compare home charging, public charging, gas savings, kWh per mile, and annual driving cost.
I am comparing heat pump vs gas
Estimate heating cost, efficiency, climate fit, and savings before replacing HVAC.
I need to cut demand charges
Estimate peak shaving savings, demand-charge reduction, battery kWh, payback, and interval-data sizing.
I need rebates or tax credits
Check federal and state incentives for solar, EVs, heat pumps, batteries, and electrification.
Featured Local Energy Benchmarks
Local calculators connect equipment usage, solar output, and electricity rates to city-specific cost decisions.
Solar Savings in Irving, TX
City-level solar payback, bill savings, and electricity-rate assumptions for North Texas homes.
Central Vacuum Energy Cost in Babylon, NY
Appliance-level monthly cost using local electricity pricing and real usage assumptions.
Home Office Energy Cost in Brockton, MA
Work-from-home electricity cost for computers, monitors, lighting, and local utility rates.
28
Free Tools
50
States + DC
EIA/DOE
Data Sources
0
Data Stored
All Energy Calculators
Organized by category. Click any tool to get started.
Solar
7 toolsPanels from annual kWh, sun hours & roof area
Monthly and annual savings from going solar
Years until panels pay for themselves
Levelized solar cost per kWh
Backup battery sizing & cost
Optimize by pitch, orientation & shading
State-specific solar savings data
Home Energy
15 toolsJ to kWh, BTU & watts x time
kWh cost, watts/hour & EIA state rates
Building kBtu per square foot per year
Full monthly bill estimate by usage and rate
Compare flat vs peak/off-peak bills
Appliance and system cost by wattage and time
Total home appliance costs
Savings from LED bulbs
Annual CO2 emissions
Efficiency score & tips
Monthly bill prediction
Sizing & savings vs gas
Battery sizing for demand charges
Whole-home ROI & credits
Federal & state rebates & credits
EV & Wind
6 toolsGas vs electric cost comparison
Home & station charging costs
Real-world range estimates
Battery degradation, SOH & warranty risk
Vehicle-specific home charging costs
Turbine output & savings
Popular EV charger calculators
Vehicle-specific home charging guides
VinFast VF 9 EV Charger
123 kWh battery, 330-mile range, Level 2 home charge time, DC fast charging, and full-charge cost.
VinFast VF 8 EV Charger
87.7 kWh battery, home charging time, DC fast-charge window, annual charging cost, and install ROI.
Lucid Air Sapphire EV Charger
427-mile range, 118 kWh battery, 300 kW DC fast charging, home charge cost, and charger payback.
Mercedes-Benz CLA EV Charger
CLA Electric range, 9.6 kW AC charging, 320 kW DC fast charging, cost per full charge, and NACS notes.
Cadillac Celestiq EV Charger
111 kWh battery, 303-mile range, NACS/CCS notes, home charging cost, DC fast charging, and install ROI.
Rivian R2S EV Charger
300-mile range estimate, 75 kWh battery, NACS charging, Level 2 home charge time, and yearly charging cost.
Energy Research & Data Hubs
Use these guides after the calculators to compare rates, incentives, household usage, EV credits, and upgrade timing with current public-data baselines.
Energy & Solar Statistics 2026
Electricity rates, household usage, renewable generation, EV charging, solar adoption, and cost benchmarks.
Electricity Rates by State
Rank current residential electricity rates by state using EIA data and compare high-cost vs low-cost regions.
Complete Guide to Energy Savings
A practical workflow for lowering bills with rate checks, appliance changes, HVAC upgrades, solar, and EV planning.
EV Federal Tax Credit 2026
Check clean vehicle credit rules, eligibility limits, vehicle qualification, and timing before buying an EV.
Heat Pump Tax Credit 2026
Compare federal heat pump credit rules, ENERGY STAR requirements, climate fit, and incentive stacking.
Free Electricity Rates Widget
Embed the current state electricity-rate table on blogs, local news sites, or energy resources with attribution.
Energy Data Expertise
Review JouleIO source standards, EIA/DOE/EPA methodology, update cadence, and editorial review process.
Energy & Solar by the Numbers
17.65¢
avg U.S. residential electricity rate/kWh (EIA 2026-02)
23.4%
of U.S. electricity from renewables (EIA, 2025)
10,500
kWh avg annual household usage (EIA, 2025)
$0.05
/kWh home EV charging vs $0.15/mile gas (DOE)
JouleIO is the most comprehensive free energy calculator suite available online. With 28 calculators covering joule conversion, solar energy, LCOE, electricity costs, time-of-use bill comparison, electric vehicles, EV battery health, wind power, peak shaving, and carbon footprint, JouleIO eliminates the need for multiple apps or paid energy audit services. Every calculation runs instantly in your browser using real-world data from the EIA, DOE, SEIA, and EPA.
Whether you're estimating solar savings, calculating electricity costs, comparing EV vs gas, or running a home energy audit, JouleIO delivers accurate results in seconds. For mortgage tools, visit Amortio. For tax planning, see LevyIO. For construction estimates, try HammerIO.
From the Blog
View all articles →Solar Panel Guide: Everything You Need to Know
Costs, savings, installation, and whether solar is right for you.
EVEV Charging Guide: Home, Public & Costs
Level 1 vs 2 vs 3 charging, home setup, and cost comparison.
Energy SavingsHow to Reduce Your Electricity Bill
Practical tips to cut energy costs by 20-40% this year.
Frequently Asked Questions
What is JouleIO?
JouleIO is a free collection of 28 solar, energy, and EV calculators. Convert joules, estimate solar savings, calculate LCOE, compare TOU rates and EV charging options, estimate EV battery health, and measure your carbon footprint — all in your browser.
How accurate are the energy estimates?
Our calculators use EIA electricity rates, SEIA solar data, and EPA emission factors. Results are planning estimates — get professional quotes for exact costs.
What official data sources does JouleIO use?
JouleIO uses EIA electricity data, NREL PVWatts solar assumptions, BLS household energy price context, EPA greenhouse gas equivalencies, and DOE Energy Saver guidance. The current homepage electricity-rate baseline is 17.65 cents/kWh for EIA 2026-02.
Is my data private?
Yes. All calculations happen locally in your browser. Your energy usage and other data never leave your device.
Which calculator should I start with?
Try the Solar Savings Calculator to see if solar makes sense, or the Electric Bill Estimator to understand your current costs.