Ohm's Law & Power Calculator
Calculate voltage (V), current (I), resistance (R), and electric power (P) across DC and single-phase circuits.
Enter Your Dimensions
US • ftHow We Calculated This
• Ensure circuit breakers and wiring gauges are rated for at least 125% of continuous current load.
Formula & Volumetric Method
V = I × R, P = V × I = I² × R = V² ÷ R. Enter any two values to solve for the remaining parameters.
Calculations are performed strictly using standard civil engineering constants. Volumetric outputs are normalized to true compaction rates, ensuring purchased quantities match jobsite yields.
Jobsite Engineering Guidelines
- V (Voltage) in Volts, I (Current) in Amperes, R (Resistance) in Ohms, P (Power) in Watts.
- Watts convert directly to electrical consumption: 1,000 Watts for 1 hour = 1 kWh.
Frequently Asked Questions
How accurate is the Ohm's Law & Power Calculator for ordering materials?
Our calculations match standard store packaging sizes in the US, Canada, UK, and Australia. We include a safety waste buffer (default 8% to 12%) so you do not run short due to uneven ground or spillage.
Why should I add extra for waste when ordering?
Uneven ground, cutting scrap, and leftover mix in the wheelbarrow or mixer drum consume an extra 5% to 15% of material. Ordering only the exact measurement usually leaves you short, which can lead to expensive extra delivery fees.
Does this calculator support both Imperial and Metric units?
Yes. You can switch between US Customary (feet, inches, cubic yards, pounds), Canadian units, UK metric, and Australian standards using the region selector in the header or the unit dropdown on each input.