Starting in R2022a, you can use the fontsize function to change the font size within a figure or for a particular object, such as a legend. You can set the font size to a specific number, or you can incrementally increase/decrease the size of all the text for the object while maintaining relative size differences.
For example, this code creates a plot and a legend and sets the legend's font size to 14 points.
plot(rand(4))
lgd = legend('One','Two','Three','Four');
fontsize(lgd,14,'points')
This code decreases the font size by a factor of 0.9.
fontsize(lgd,'decrease')
R2022a also includes the fontname function, which enables you to change all the fonts within the figure or for a particular object in the figure.
For previous releases:
You can change the font size for a MATLAB legend by setting the 'FontSize' property of the Legend object.
For example, plot four lines. Create a legend and assign the Legend object to the variable 'lgd'. Then, use dot notation to access the 'FontSize' property and set the value to 14 points.
plot(rand(4))
lgd = legend('One','Two','Three','Four');
lgd.FontSize = 14;
Alternatively, you can specify the 'FontSize' property using a name-value pair argument in the 'legend' command. When including name-value pair arguments, include the legend labels in a cell array. For example:
legend({'One','Two','Three','Four'},'FontSize',14)
