Energy / Solar / Backup
Energy cost, appliance use, EV charging, solar sizing, payback, batteries, inverters and UPS estimates.
SpecCalc Hub
Electrical calculators and references
Search grouped calculators, converters, diagrams and references. Results are informational estimates only and must be verified before real-world decisions.
Which calculator should I choose?
For cost questions, start with Electricity Cost (e.g. monthly bills) or Appliance Energy Cost (e.g. TVs, heaters). For backup time, use Battery Runtime (for DC batteries) or UPS Runtime (for AC electronics). For cable topics, use Voltage Drop or Wire Size Estimate as preliminary planning tools only.
Important starting points
Catalog groups
Cable & Wiring
Voltage drop, wire-size estimates, cable loss, maximum length and AWG conversion with professional verification notes.
Motors
Motor current, power, speed, slip and capacitor planning context.
Electronics & Pinouts
Ohm's Law, resistor, inductor and capacitor codes, voltage divider, LED resistor and connector pin references.
General Electrical
Power triangle, kW/kVA/kVAr, power factor and transformer reference calculations.
References
IP ratings, grounding systems, electrical symbols, units and connection diagrams.
Calculator catalog FAQ
Are results final engineering design?
No. Results are informational estimates and high-risk topics require qualified professional verification.
Are calculator inputs stored?
No account is required and calculation history is not saved server-side.
Recommended calculators
10CalculationPDF
Electricity Cost Calculator
Calculate electricity cost from known kWh, or estimate consumption from appliance power and time. Enter your own flat tariff and currency.
CalculationPDF
Appliance Energy Cost Calculator
Estimate appliance cost using quantity, rated power, duty cycle, runtime, and tariff.
CalculationPDF
Solar Panel Size Calculator
Estimate PV watts and whole-panel count from daily energy, peak sun hours, system losses and solar coverage.
CalculationPDF
Solar Payback Calculator
Estimate simple solar payback from system cost, incentives, generation, and rates.
CalculationPDF
Battery Runtime Calculator: Ah, Wh, Load & Efficiency
Estimate battery runtime from voltage, amp-hours, discharge depth, efficiency and load. Separate nominal energy from the energy actually available.
CalculationPDF
Inverter Size Calculator
Estimate continuous and surge inverter size from load, surge, margin, and power factor.
CalculationPDF
UPS Runtime Calculator
Estimate UPS runtime from battery configuration, load, efficiency, and usable capacity.
CalculationPDF
EV Home Charging Cost Calculator
Estimate EV charging energy, cost, and time from battery size, SOC, efficiency, tariff, and charger power.
CalculationMedium-high riskPDF
Voltage Drop Calculator
Estimate DC, single-phase and three-phase voltage drop, percent loss and load voltage from cable size, length, current and material in simplified PF=1 mode.
CalculationHigh riskPDF
Wire Size Estimate Calculator
Estimate conductor area from voltage drop only. This is not final cable selection.
Energy, solar and backup power
9CalculationPDF
Electricity Cost Calculator
Calculate electricity cost from known kWh, or estimate consumption from appliance power and time. Enter your own flat tariff and currency.
CalculationPDF
Appliance Energy Cost Calculator
Estimate appliance cost using quantity, rated power, duty cycle, runtime, and tariff.
CalculationPDF
Solar Panel Size Calculator
Estimate PV watts and whole-panel count from daily energy, peak sun hours, system losses and solar coverage.
CalculationPDF
Solar Payback Calculator
Estimate simple solar payback from system cost, incentives, generation, and rates.
CalculationPDF
Battery Runtime Calculator: Ah, Wh, Load & Efficiency
Estimate battery runtime from voltage, amp-hours, discharge depth, efficiency and load. Separate nominal energy from the energy actually available.
CalculationPDF
Inverter Size Calculator
Estimate continuous and surge inverter size from load, surge, margin, and power factor.
CalculationPDF
UPS Runtime Calculator
Estimate UPS runtime from battery configuration, load, efficiency, and usable capacity.
CalculationPDF
EV Home Charging Cost Calculator
Estimate EV charging energy, cost, and time from battery size, SOC, efficiency, tariff, and charger power.
Calculation
VanLife Trip Planner Calculator
Estimate fuel, water, daily power needs, battery and solar context, plus the total road-trip budget before opening routes on VanLife.uz.
Cable and wiring
7CalculationMedium-high riskPDF
Voltage Drop Calculator
Estimate DC, single-phase and three-phase voltage drop, percent loss and load voltage from cable size, length, current and material in simplified PF=1 mode.
CalculationHigh riskPDF
Wire Size Estimate Calculator
Estimate conductor area from voltage drop only. This is not final cable selection.
CalculationMedium-high risk
Maximum Cable Length Calculator: Voltage-Drop Limit
Estimate one-way cable length for a chosen voltage-drop limit. This is a voltage-drop calculation, not an ampacity or protection approval.
CalculationHigh risk
Cable Ampacity Estimate
Preliminary ampacity context with installation and derating reminders.
CalculationMedium-high risk
Conduit Fill / Pipe Diameter Estimate
Reference workflow for estimating conduit fill before professional verification.
Conversion
AWG to mm² Converter
Convert common AWG conductor sizes to diameter and approximate cross-section.
CalculationMedium risk
Cable Power Loss Calculator: I²R, kWh & Cost
Calculate resistive electrical cable losses and their energy cost. RF coaxial antenna attenuation in dB is a different calculation.
Motors
6CalculationMedium risk
Motor Current Estimate
Estimate motor current from power, voltage, efficiency and power factor assumptions.
CalculationMedium risk
Three-Phase Motor Power Calculator
Reference calculation for three-phase real power from voltage, current and power factor.
CalculationHigh risk
Motor Capacitor Estimate
Educational reference for three-phase motor on single-phase supply capacitor estimates.
Calculation
Synchronous Speed Calculator: 120f/p, 50 Hz & 60 Hz
Find motor rotating-field speed from frequency and total poles. Compare 50 Hz and 60 Hz examples without confusing poles with pole pairs.
Calculation
Motor Slip Calculator: Synchronous vs Rotor Speed
Calculate induction-motor slip in percent from synchronous and measured rotor speeds. Keep field speed, shaft speed and pole count distinct.
Conversion
kW to HP Converter: Mechanical Horsepower & Motor Examples
Convert kW to mechanical hp or hp to kW with one input. See 7.5 kW and 3050 kW examples, metric PS differences and motor nameplate limitations.
Electronics and pinouts
12Reference
USB Pinout Reference
Simplified educational USB pinout reference.
Reference
RJ45 T568A/B Pinout Reference
Compare all eight 8P8C contact colours for T568A and T568B. The green and orange pairs exchange positions; blue and brown stay the same.
Reference
HDMI Pinout Reference
HDMI connector signal group reference.
Reference
DisplayPort Pinout: 20 Pins, AUX, HPD & Pin 20
Read a numbered full-size DisplayPort source pinout with Main Link, AUX, HPD and DP_PWR explained. Distinguish connector numbering from cable continuity.
Reference
VGA Pinout Reference
VGA connector signal reference.
ReferenceMedium risk
SATA/Molex Pinout Reference
PC power connector reference.
Calculation
Resistor Color Code Calculator
Decode common 4-band resistor color codes.
Calculation
Inductor Color Code Calculator
Reference decoder for common inductor bands.
Calculation
Capacitor Code Calculator
Decode common three-digit capacitor markings.
CalculationMedium risk
LED Resistor Calculator
Estimate a series resistor for a simple LED circuit.
Calculation
Voltage Divider Calculator
Calculate ideal two-resistor voltage divider output.
ConversionMedium risk
Star/Delta Resistance Conversion
Reference formulas for balanced star and delta resistance conversion.
General electrical
10Calculation
Ohm's Law Calculator
Calculate voltage, current, resistance and power relationships.
CalculationMedium risk
Power Calculator DC / Single-phase / Three-phase
Reference formulas for common power relationships.
ConversionMedium risk
kW, kVA & kVAr Calculator: Power Factor Triangle
Relate active, apparent and reactive power using the selected inputs. kVAr is power; kVArh is accumulated reactive energy.
CalculationMedium-high risk
Power Factor Correction Calculator
Preliminary capacitor kVAr estimate for target power factor.
CalculationHigh risk
Grounding Resistance Estimate
High-risk reference for grounding resistance concepts.
CalculationHigh risk
Short-Circuit Current Estimate
High-risk reference for short-circuit estimation concepts.
CalculationMedium-high risk
Single-phase Transformer Calculator
Reference formulas for ideal transformer voltage, current and turns ratios.
CalculationMedium-high risk
Reactive Power Compensation Calculator
Preliminary calculator for reactive power compensation and kVAr capacitor sizing.
Conversion
Lighting Unit Converter
Reference converter context for lumen, lux and area relationships.
Conversion
IP Rating Decoder: IP65, IP67, IP68 & IPX7 Explained
Decode both IP characteristics, including X for unspecified protection. Compare dust, water jets and immersion without assuming a waterproof guarantee.
References and standards
7Reference
IP Protection Classes Reference
Reference overview of ingress protection rating structure.
ReferenceHigh risk
Grounding System Types Reference
TN-C, TN-S, TN-C-S, TT and IT educational diagrams.
Reference
Electrical Symbols: IEC vs ANSI, Names & Functions
Compare common IEC-style and ANSI-style electrical symbols with clear vector sketches. Identify resistors, contacts, motors, fuses and earth references.
Reference
AWG Conversion Table
Reference table for AWG diameter and approximate area.
ReferenceHigh risk
Cable Color References
Country-dependent cable color reference with strict verification note.
Reference
Electrical Units Reference
Plain-language reference for common electrical units.
ReferenceMedium-high risk
Three-Phase Connection Diagrams
Original simplified star and delta connection diagrams.