How do I make a Smith chart from impedance?

Paste resistance and reactance in ohms and set Z0. The tool normalizes z = Z/Z0, computes Γ = (z − 1)/(z + 1), and draws the point on the chart. Download the SVG for a report or slide.

What does a Smith chart tell you?

It shows how far a load is from a match, whether it looks inductive or capacitive, and what VSWR that |Γ| implies. Constant-r circles and constant-x arcs let you read normalized impedance without converting by hand.

Is this the same as a Nyquist plot?

No. A Nyquist plot is Re(G(jω)) versus Im(G(jω)) for a transfer function. A Smith chart is the reflection coefficient of an impedance on a line. Use the Nyquist plot generator for G(s).

Does this design a matching network?

No. It does not choose stubs, lumped L-sections, or a tuner. It plots the load you enter and reports |Γ|, angle, VSWR, and return loss.

Can I plot reflection coefficient instead of ohms?

Yes. Switch to Reflection Γ and paste real/imaginary parts or magnitude and degrees. Z0 is still used to recover the equivalent impedance shown in the readout.

Is the Smith chart generator free?

The precise, number-driven chart is free to use and free to download as SVG, with no sign-up. Sign in only if you want AI illustrations or other ConceptViz generation tools.

RF Engineering Tool

Smith Chart Generator for impedance

Free Smith chart generator. Paste impedance or reflection coefficient to draw the chart, then download SVG.

Impedance Z or reflection ΓConstant-r and constant-x circlesVSWR and return-loss readoutDownload a watermark-free SVG — free

Paste impedance or reflection coefficient — renders Γ on a Smith chart as SVG, free

Impedance or Gamma

Paste R and X in ohms, or Γ as real/imag or mag/deg. This tool does not synthesize a matching network.

R, X table (ohms)Z0 (ohms)

TitleAdmittance overlay (constant g)

n=1 · match: |Γ|=0.000, ∠0.0°, VSWR=1.000. VSWR and return loss are diagnostics, not a matching design.

Smith Chart Examples

The first four are exact engine renders from impedance. The last two are AI illustrations of Illustration mode.

View:

Matched load

Exact engine render — Z = 50 Ω on a 50 Ω line, Γ = 0 at the center.

smithmatched

Inductive load

Exact engine render — z = 1 + j, Γ = 0.2 + 0.4j.

smithinductive

Capacitive load

Exact engine render — z = 0.5 − j0.5.

smithcapacitive

Short circuit

Exact engine render — Z = 0, Γ = −1.

smithshort

AI illustration — impedance

AI illustration of Illustration mode — visual mockup, not computed from Z or Γ.

aiillustration

AI illustration — teaching

AI illustration of Illustration mode — visual mockup, not a matching design.

aiillustrationteaching

What is a Smith chart?

A Smith chart is the reflection coefficient Γ plotted on the complex plane, with circles of constant normalized resistance r and arcs of constant normalized reactance x. Radio-frequency engineers use it to read impedance, VSWR, and matching paths on a transmission line. This page maps Z = R + jX through Γ = (z − 1)/(z + 1) with z = Z/Z0, or plots Γ you already have. It is not a control-system Nyquist plot of G(jω), and it is not an electrochemical impedance plot of Z′ versus −Z″.

How to enter Z or Γ

Impedance mode wants R and X in ohms plus a characteristic impedance Z0 (default 50 Ω). Reflection mode wants Γ as real and imaginary parts, or as magnitude and angle in degrees.
Paste one row for a single load, or several rows to draw a locus. The red marker is the plotted point. SC is the short-circuit rim (Γ = −1), OC is the open-circuit rim (Γ = +1), and the center is a matched load.
This page does not synthesize stubs, L-sections, or a matching network. VSWR and return loss are printed as diagnostics from |Γ|.

Smith chart versus a Nyquist plot

Both live on a complex plane, but they are different numbers. A Smith chart is Γ of a load on a transmission line. A Nyquist plot is G(jω) of a transfer function. Use this page for RF impedance. Use the Nyquist plot generator for control-system polar frequency response, and the Bode plot generator for magnitude and phase versus frequency.

Export

Download a scalable SVG with no watermark and no account required for the precise chart. The AI Illustration tab is only for slides when you do not have numbers yet — it will not match your Z or Γ.