Metered history
Twelve months of kWh, plus interval demand data for commercial sites. Estimates end where metering begins.
Methodology
How Electrician1001 calculates.
Explicit-input models with visible formulas, dated baselines, machine-checked test cases, and a stated verification boundary. Screening-grade arithmetic for electrical work, not revenue metering.
The principle
Every result must be reproducible from the inputs on the page.
Each calculator is a fixed formula over labeled inputs. There are no hidden scores, no black-box adjustments, and no location lookups: the numbers you type, plus the stated defaults, fully determine the outputs. Every calculator page shows its formula, and every calculator ships with automated test cases that fixed inputs must reproduce before publication.
Units and conventions
One consistent system across all eighteen tools.
Power vs energy
kW measures rate of use; kWh measures accumulated use. Cost always derives from kWh multiplied by a rate, never from kW alone, except demand charges, which price the peak kW over the utility interval (usually 15 minutes).
Money handling
Rates are entered in cents per kWh and converted once, at a single documented step, to dollars. Displayed money rounds to cents; intermediate values keep full precision so chained steps do not drift.
Duty cycle
Cycling equipment (compressors, thermostats, chargers) is modeled as nameplate power times effective run hours. Where duty is uncertain, the input stays editable and the assumption stays labeled, rather than being buried in a fixed factor.
Precision statement
Outputs are screening-grade: good enough to rank options, size a first pass, or check a quote. They are not revenue-grade metering and do not replace interval data, load studies, or short-circuit analysis.
Method by category
What each tool family models, and what it assumes.
Circuits
Single-phase power relations (P = V x I) at the entered voltage. The 15A reference flags the 80% continuous-load rule: a result near 12A means the circuit is at its continuous limit, not that it has headroom.
Load and appliances
Connected load sums nameplate kW; running cost multiplies by hours, days, and duty cycle. Estimates assume steady operation at rated power unless the duty input says otherwise.
Rates and bills
Flat, tiered, and time-of-use structures are modeled exactly as entered: thresholds, windows, shares, and fixed fees. State and national averages are dated baselines for comparison, never substitutes for the tariff sheet.
Commercial power
Energy, demand, and fee portions are separated so the dominant one is visible. Load factor divides average load by peak; power-factor penalties scale billed demand against the utility threshold. Ratchet and rider specifics must come from the tariff.
Solar
Array size derives from target offset, sun hours, and derate; payback divides net cost after credits by first-year savings, with panel degradation and rate escalation carried through the lifetime view. Shading, orientation, and net-metering rules are site-specific and stay outside the model.
EV charging
Home and public energy shares blend into one effective rate per kWh, then per mile, against gasoline cost per mile plus a maintenance allowance. Charging efficiency losses and demand fees at public stations belong in verification.
Sources and baselines
Dated numbers, named sources, annual review.
Usage and rate averages
National figures (for example, average household kWh and cents per kWh) come from U.S. Energy Information Administration tables and carry their data year. A yearly site review checks defaults against the newest release.
Code references
Where practice is discussed, the National Electrical Code is cited as context for why a rule exists, never as installation instruction. The locally adopted code and the authority having jurisdiction always govern.
Equipment figures
Typical wattages, COP ranges, and lifespans are labeled as starting points. Nameplate data and manufacturer sheets replace them during verification.
Verification protocol
Replace these five before relying on any result.
Current tariff sheet
Rates, tiers, windows, fixed fees, demand charges, ratchets, and riders exactly as billed this month.
Nameplate facts
Actual wattage, voltage, efficiency ratings, and duty behavior of the installed equipment.
Site conditions
Shading, orientation, service capacity, and coincident loads that no generic model can see.
Qualified review
A licensed electrician, installer, or utility advisor confirms the conclusion before money is spent.
Rate baselines are dated starting points, not live utility feeds. Calculator results are screening outputs, not utility bills, quotes, permits, or guarantees.
Known limits
What these tools deliberately do not do.
No code compliance
Nothing here determines whether an installation meets code. Sizing, protection, wiring methods, and clearances are field decisions under the AHJ.
No coincident-peak modeling
Load tools sum connected or average loads. Which loads coincide in the same 15-minute interval requires metered data the tools do not have.
No forecasts
Escalation and degradation inputs project arithmetic, not the future. They show sensitivity to assumptions; they do not predict rates, weather, or performance.
No account data
Public baselines never describe your account. Two neighbors on different tariffs can have legitimately different bills for identical usage.