Learn how to calculate molarity from moles and volume or from mass and molar mass. Includes C = n/V, worked lab examples, unit conversions, and a free concentration calculator.
Learn how to use the half-life formula to find remaining amount, elapsed time, or half-life. Includes carbon-14 dating, medical isotopes, worked examples, and a free half-life calculator.
Transformers, generators, and UPS units are rated in kVA (apparent power) so their current capability is clear no matter the load power factor. Here is how kVA turns into line amps on single-phase and three-phase systems.
Plan your EV charger circuit: how 7 kW and 22 kW charger power translates to amps on single-phase and three-phase supplies, and how to check numbers before you talk to an electrician.
Estimate the generator size you need from total running watts, motor starting surge, and a planning margin. Understand running vs surge ratings, the largest motor method, and what a generator sizing tool cannot replace.
Find the minimum AWG or kcmil conductor size that satisfies both ampacity and voltage drop limits. Understand the two sizing criteria, copper vs aluminum, and when voltage drop — not ampacity — governs your wire choice.
Estimate the right circuit breaker amp rating from load current or from watts, voltage, phase, and power factor. Understand the 125% continuous load rule, standard breaker sizes, and what this tool does and does not replace.
Calculate daily kWh from your array size (kWp), peak sun hours, and system performance. Understand what these numbers mean and how to use them for planning a solar installation.
Estimate battery runtime from watt-hours and load, or from amp-hours and voltage. Understand efficiency losses, Peukert effects, and how to plan any DC or off-grid system.
Calculate electricity cost from kWh and your rate, or derive kWh from watts and hours. Understand exactly what any appliance or usage period costs on your bill.
Watts (W) measure power and kWh measure energy. Convert using kWh = W × h ÷ 1,000 and estimate total energy for a given runtime.
kWh measures energy, watts measure power. Learn the time-based relationship between them, why electricity bills use kWh, and how to estimate average watts from your total using W = kWh × 1,000 ÷ h.
Learn Ohm's law V = I × R and power P = V × I = I²R = V² ÷ R. Six ways to pick two knowns from voltage, current, resistance, and watts — plus a free all-in-one calculator that runs in your browser.
You cannot get watts from volts alone. Learn P = V × I for DC, P = V × I × PF for single-phase AC, P = √3 × V × I × PF for balanced three-phase (line-to-line), and P = V² ÷ R for resistive loads — plus a free volts-to-watts calculator in your browser.
You cannot get volts from amps alone. Learn when to use V = P ÷ I (DC and AC with power factor), V = P ÷ (√3 × I × PF) for three-phase, and V = I × R with Ohm's law — plus a free amps-to-volts calculator in your browser.
Decode voltage, watts, VA, and current on appliance labels. Learn when to use I = P ÷ V vs power factor for AC, and use Tooladex’s free watts-to-amps calculator for breakers and cords.
Learn how to convert amps and volts to watts using P = V × I for DC, power factor for AC, and √3 for three-phase. Includes worked examples and a free amps-to-watts calculator that runs in your browser.
Learn how to calculate density using mass and volume, solve for mass or volume when density is known, and understand density units. Includes real-world examples and a free density calculator tool.
Learn how to calculate mean, median, mode, and range from a list of numbers. Understand different types of averages and when to use each. Use our free Average Calculator with multiple input formats and detailed statistical insights.
Track your academic performance with our free Grade Calculator. Calculate current grades, determine what you need on final exams, compute weighted averages, and calculate GPA instantly.
Learn how to work with fractions, perform fraction arithmetic, and simplify fractions. Use our free Fraction Calculator to add, subtract, multiply, divide, and convert fractions and decimals instantly.
Learn how to calculate pH, pOH, H+ concentration, and OH- concentration quickly and accurately. Includes examples, formulas, and our free pH calculator tool.
Learn how to calculate molecular weight of chemical compounds quickly and accurately. Includes examples, formulas, and our free molecular weight calculator tool.