Budget set is a set of all possible combinations of the two goods the consumer can buy from his income at given prices; the cost of these combinations is exactly equal to the income of the consumer or less than it.

Now, let’s say the income of a consumer is Rs 1000 and he has to buy apples and oranges. The price per kg apple is Rs 50 and apple is Rs 20. The possible outcomes could be

These set of combinations will be called budget set.

The right angle triangle AOB as shown in the following figure is called budget set, it is formed between the budget line and the two axis