NodeA point that stays still. Both string ends are nodes too.
AntinodeA point that moves the most. It lies midway between two nodes.
WavelengthThe length of two loops in a row. Neighboring nodes are half of it apart.
Half a wavelengthThe distance from one node to the next.
AmplitudeHow far an antinode moves from the rest position.
Rest positionWhere the string lies when it is not vibrating.
Fixed endWhere the string is held and cannot move. A node forms here.
Harmonics 3
First harmonic (fundamental)One antinode between the two ends. Also called the fundamental.
Second harmonicTwo antinodes, with a node in the middle of the string.
Third harmonicThree antinodes, with two nodes between the ends.
How this list was compiled: Every name and fact checked on 2026-10-01 and read again on 2026-10-02, a name kept only where two independent sources use it. (1) Wikipedia, text only: Standing wave, https://en.wikipedia.org/wiki/Standing_wave ; Node (physics), https://en.wikipedia.org/wiki/Node_(physics) ; Harmonic, https://en.wikipedia.org/wiki/Harmonic (nodes are where the amplitude is least and antinodes where it is greatest, midway between the nodes; two neighboring nodes are half a wavelength apart; a string with two fixed ends; the fundamental has a wavelength twice the length of the string; n antinodes and n + 1 nodes counting the fixed ends; 1st, 2nd and 3rd harmonic; the 2nd harmonic is the 1st overtone). (2) The Physics Classroom, Waves lesson 4: Nodes and Anti-nodes, https://www.physicsclassroom.com/class/waves/Lesson-4/Nodes-and-Anti-nodes ; Harmonics and Patterns, https://www.physicsclassroom.com/class/waves/Lesson-4/Harmonics-and-Patterns ; Mathematics of Standing Waves, https://www.physicsclassroom.com/class/waves/Lesson-4/Mathematics-of-Standing-Waves (nodes are points of no displacement, antinodes points of most displacement above and below the rest position; a standing wave is drawn as the shape of the medium at one instant and half a cycle later; first, second and third harmonic with their numbers of nodes and antinodes; one loop is half a wavelength). (3) University of New South Wales, School of Physics, Strings, standing waves and harmonics, https://newt.phys.unsw.edu.au/jw/strings.html (nodes never move and lie half a wavelength apart; antinodes halfway between them have maximum amplitude; a string fixed at both ends has a node at each end; the fundamental has a wavelength of twice the string, the second and third harmonics two and three times its frequency). (4) HyperPhysics, Georgia State University, Standing Waves, http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/standw.html , and Standing Waves on a String, http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/string.html (nodes and antinodes as the points of least and greatest vibration; reflection from a fixed end; the fundamental and the second harmonic of a stretched string). (5) BBC Bitesize, Properties of waves, https://www.bbc.co.uk/bitesize/guides/zgf97p3/revision/1 (the rest position is the undisturbed position when nothing is vibrating; amplitude is the most a point of a wave is displaced from its rest position). Licence: own work
The drawing: Drawn for this site on 2026-10-01 from sine curves; nothing traced. Licence: own work
How it works
To draw a standing wave and label the nodes and antinodes, start from this picture: a string held at both ends, shown at its two extremes. The names are on the drawing; press Quiz me to tap each part.
Read the full guide
Read the drawing
The solid line is the string at one instant. The dotted line is the same string half a cycle later. Where the two lines cross, the string stays still: a node. Midway between two nodes it swings farthest: an antinode. Neighboring nodes are half a wavelength apart.
Draw and label it yourself
Rule a straight rest position between two fixed ends. Mark the nodes at even spaces, the two ends among them. Draw one wavy line through the nodes and its mirror image. Label each crossing a node and each widest point an antinode.
On a string fixed at both ends, count the antinodes to name the harmonic: one is the first, two the second, three the third.
Questions and answers
What are nodes and antinodes in a standing wave?
A node is a point that does not move. An antinode is a point that moves the most, midway between two nodes. Nodes and antinodes alternate along the string and keep their places.
How far apart are the nodes of a standing wave?
Half a wavelength. One whole wavelength reaches from a node past the next node to the one after it, so it covers two loops of the string.
How many nodes and antinodes does each harmonic have?
On a string fixed at both ends, the first harmonic has two nodes and one antinode, the second has three nodes and two antinodes, and the third has four nodes and three antinodes. The ends are counted as nodes.
What is the fundamental of a string?
Its first harmonic, the standing wave with the lowest frequency: one antinode between the two fixed ends. Its wavelength is two string lengths. The second and third harmonics have two and three times its frequency.
How is a standing wave made?
Two waves of the same frequency travel along the string in opposite directions, one of them reflected from a fixed end. Where they always cancel there is a node; where they add up most there is an antinode.