MYEFO explained: the budget bottom line in 4 charts

The budget deficit for this financial year will be $40.4 billion, more than $10 billion larger than forecast in May, Treasurer Joe Hockey has revealed.

See how the forecast bottom line revealed in today's Mid-Year Economic and Fiscal Outlook compares to previous outlooks.

The MYEFO budget update shows the federal government will receive $31.6 billion less in tax receipts over the next four years - a fall mostly driven by a 30 per cent collapse in iron ore prices and weaker than expected wage growth.

Weaker growth in wages and employment are forecast to lower tax receipts by $2.3 billion this financial year and $8.6 billion over the forward estimates.