Impedance Reactance Chart

Use this impedance and reactance chart after the calculator result to document resistance, reactance direction, frequency, circuit model, and phase assumptions.

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Quick reference table

Use these formulas: XL = 2 pi f L and XC = 1/(2 pi f C) before combining reactance with resistance. At 60 Hz, 100 mH gives XL = 37.7 ohms and 100 uF gives XC = 26.5 ohms; Z = sqrt(R^2 + X^2) for a simple series model.

Reactance behavior in AC circuits

Reactance behavior in AC circuits
Quantity	Formula	Trend
Resistance	R	Simple model does not depend on frequency
Inductive reactance	XL = 2 pi f L	Increases as frequency increases
Capacitive reactance	XC = 1 / (2 pi f C)	Decreases as frequency increases
Net reactance	X = XL - XC	Positive is inductive, negative is capacitive
Impedance magnitude	Z = sqrt(R^2 + X^2)	Combines resistance and net reactance

AC calculator result checks

AC calculator result checks
Result shows	Record next	Why it matters
Inductive result	Frequency, inductance, and winding resistance	Real coils are not pure inductors
Capacitive result	Capacitance, frequency, and tolerance	Capacitor tolerance can change reactance materially
Near resonance	Whether XL and XC nearly cancel	Small changes can create large current or voltage effects
Power factor concern	Net reactance direction and real-power load context	Impedance magnitude alone does not explain the whole load

Formula basis

XL = 2 x pi x f x L. XC = 1 / (2 x pi x f x C). X = XL - XC. Z = sqrt(R^2 + X^2) for a simple series model.

XL is inductive reactance in ohms.
XC is capacitive reactance in ohms.
f is frequency in hertz.
Z is impedance magnitude for the selected circuit model.

Worked examples

Inductive reactance at 60 HzFor a 0.1 H inductor at 60 Hz, XL = 2 x pi x 60 x 0.1 = about 37.7 ohms before combining with winding resistance.

Capacitive reactance at 60 HzFor a 100 uF capacitor at 60 Hz, XC = 1 / (2 x pi x 60 x 0.0001) = about 26.5 ohms before tolerance and circuit model are checked.

Assumptions. Balanced load and line-to-line voltage assumptions behind this chart.

The formulas describe simplified AC circuit models and do not cover every network topology.
Real components can have tolerance, temperature effects, saturation, winding resistance, equivalent series resistance, and parasitic effects.
Use equipment data and measurements before relying on impedance values for protective-device, power-quality, or performance decisions.

Code and standard notes. Planning limits that should be checked before final equipment selection.

Use equipment data, project measurements, and responsible engineering review before using impedance values for protective-device or power-quality decisions.

How to use this chart

1Identify the circuit modelRecord whether the calculator result is resistance-only, inductive, capacitive, series RLC, parallel RLC, or another AC circuit model.

2Document frequencyReactance changes with frequency, so document whether the calculation uses 60 Hz or another project-specific value.

3Record reactance directionAfter the calculator result, note whether the net behavior is inductive, capacitive, or near cancellation before tying it to power-factor work.

Worksheet checklist. Record source basis, review gaps, and assumptions before using the chart result.

Record component valuesWrite resistance, inductance, capacitance, tolerance, and real-component notes before selecting the formula path.
Record operating frequencyUse the frequency that applies to the circuit or measurement rather than assuming all AC work is identical.
Tie to the next calculatorUse impedance results with power factor, RC timing, or power-quality calculators only after the model and units are clear.

Common mistakes to avoid. Review these before turning chart current into an equipment decision.

Treating ohms of resistance and ohms of reactance as the same physical effect in an AC circuit.
Forgetting that capacitive and inductive reactance move in opposite directions as frequency changes.
Using the simple series impedance formula for a parallel network or equipment model that needs a different calculator path.

Frequently asked questions

These answers explain how to use the chart without turning a quick reference into a final design decision.

Is impedance the same as resistance?

No. Resistance is one part of impedance. AC impedance also includes reactance from inductance or capacitance.

Why does frequency matter?

Frequency changes inductive and capacitive reactance, so the same component can produce different impedance in different AC conditions.

Why record inductive or capacitive direction?

The direction helps explain power factor, resonance, and whether the circuit behavior is dominated by inductance or capacitance.

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