Phoenix 33.4° N
Year-round 33°, summer 18°, winter 48°. Snow not an issue — fix at 25° to balance summer peak load.
Solar panel tilt calculator
What's the optimal tilt angle for my solar panels?
Get the year-round optimal tilt (≈ latitude), summer tilt (latitude − 15°) and winter tilt (latitude + 15°), plus expected production gain from seasonal adjustment.
Panel Tilt & Azimuth
Solar panel tilt & azimuth optimizer
Year-round optimal tilt29.7°
Summer-optimized tilt20°
Winter-optimized tilt50°
Optimal azimuth180°
HemisphereNorthern (face south)
Results are first-pass estimates. Verify with installers, manufacturers, and utility tariffs before purchase.
How it works
How it works
- Year-round optimal tilt ≈ latitude — within 5% of true optimum for fixed-mount arrays.
- Summer tilt = latitude − 15°. Captures higher sun angle May–Aug for ~3–5% summer gain.
- Winter tilt = latitude + 15°. Reduces snow accumulation and improves Dec–Feb yield 10–25% in Zone 5+.
Worked examples
Worked examples
Boston 42.4° N
Year-round 42°, summer 27°, winter 57°. Two-position seasonal swap gains 6% annual.
Anchorage 61.2° N
Year-round 61°, winter 76°. Steep winter tilt sheds snow; near-vertical may capture albedo from snowpack.
Tilt angle FAQ
Tilt angle FAQ
What if my roof isn't at the optimal angle?
A 10° offset costs only 1–2% annual production. Most pitched roofs (15–35°) work fine for latitudes 30–45° N without tilt legs.
Does azimuth matter more than tilt?
Yes. Due south = 100%. West = 88%, east = 85%, north = 65%. Fix azimuth first, then worry about tilt.
Are tracking systems worth it?
Single-axis trackers gain 15–25%, dual-axis 30–35%. Add maintenance and cost: usually only pencils on ground-mount commercial sites.
How often should I swap seasonal tilts?
Twice a year (April and October) captures 90% of the benefit vs monthly adjustment.
Calculator directory
Choose the right EV, solar, and battery calculator
EV charging time calculator
Enter your battery capacity, starting and target state of charge, and charger output to estimate charging time, the kWh pulled from the wall, and your cost per session — all from open, transparent formulas.
Open calculatorSolar panel calculator
Size a solar PV array from your daily electricity use, local peak sun hours, system losses, and panel wattage. Also estimates roof area and an off-grid battery bank using depth-of-discharge and round-trip efficiency.
Open calculatorBattery runtime calculator
Enter your battery capacity in watt-hours, the running load, idle standby draw, usable depth-of-discharge, and inverter efficiency to estimate practical runtime for a Jackery, EcoFlow, Bluetti, APC UPS, or any custom 12 / 24 / 48 V bank.
Open calculatorHome battery backup calculator
Add up critical loads (fridge, well pump, internet, a few lights), pick how many hours per day you need them, set a target number of backup days, and the calculator returns the battery bank size and how much solar recharge offsets the draw each day.
Open calculatorEV road trip calculator
Estimate stops, charging time, and drive time from route distance, EV range, battery capacity, departure SOC, reserve SOC, target stop SOC and DC charger power.
Open calculatorSolar payback calculator
Apply the 30% federal ITC, model 0.5%/year panel degradation and 3%/year rate inflation, and see year-by-year cumulative savings until the system breaks even.
Open calculatorNet metering calculator
Compare a solar bill under traditional 1:1 net metering vs export-only credits (e.g. CA NEM 3.0). Get monthly net cost, exported kWh, self-consumption ratio, and annualized totals.
Open calculatorHeat pump vs gas calculator
Convert your annual heating demand to kWh and therms with COP and AFUE, then compare yearly fuel cost and CO₂. Uses EPA grid average 0.39 kg CO₂/kWh and 5.3 kg CO₂/therm.
Open calculatorGenerator sizing calculator
List your running watts and the largest motor (well pump, AC compressor, fridge), apply LRA-based starting surge, and add a safety factor for fuel headroom and altitude derating.
Open calculatorSolar lease vs buy calculator
Model cash purchase (with 30% ITC) versus a 25-year lease with annual escalator. Inputs: system cost, lease payment year 1, escalator %, annual production, retail rate.
Open calculatorSolar panel tilt calculator
Get the year-round optimal tilt (≈ latitude), summer tilt (latitude − 15°) and winter tilt (latitude + 15°), plus expected production gain from seasonal adjustment.
Open calculatorSolar inverter sizing calculator
NREL and SEIA recommend a DC:AC ratio of 1.15–1.30. Higher ratios cost less per AC watt but cause midday clipping. Find the sweet spot for your location.
Open calculatorWind turbine calculator
Estimate annual kWh from rotor swept area, average wind speed, air density, capacity factor and turbine efficiency. Uses the Weibull-corrected power equation.
Open calculatorEV total cost of ownership calculator
Sum purchase price (minus federal tax credit), fuel/electricity, insurance, maintenance and registration over 5 years. Default electricity 4.0 mi/kWh, gas 28 mpg.
Open calculator