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Popular: Battery Sizing · 3-Phase Power · Land Area · GPA Calculator
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- Battery Sizing CalculatorSolar, UPS & backup — Ah, kWh, DODPopular
- Solar Roof Area EstimatorPanel layout, usable area, kWp planning
- 3-Phase Power CalculatorkW, kVA, power factor — NEC compliantPopular
- Cable Size CalculatorAmpacity, voltage drop, Cu/Al — NEC/IEC
- Hybrid Inverter SizingkVA, battery bank, PV array — off-grid
- Excavation Volume CalculatorCut & fill, swell/shrink, cost estimate
- Soil Texture ClassifierUSDA triangle — sand, silt, clay
- Land Area CalculatorAcres, hectares, GPS polygon — farm usePopular
- PV String ConfigurationModule count, voltage correction, MPPT
- GPA & Grade CalculatorsWeighted GPA, grade converter, planning
- Advanced Scientific CalculatorMatrix, stats, programmer & equation modes
- Fertilizer Rate CalculatorsNPK rates, application planning, crop nutrition
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- ★★★★★
The battery sizing calculator saved me hours on a 48V off-grid system design. Accuracy is impressive for a free tool.
- ★★★★★
The 3-phase power calculator is spot-on. I use it to verify load calculations before specifying transformers. Bookmark-worthy.
- ★★★★★
Used the excavation calculator on a residential foundation project. Saved us from ordering 30% too much fill material.
- ★★★★★
The GPA calculator is clean, fast, and handles weighted grades correctly. Way better than the tools my university provides.
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