Open MathNSWGitHub ↗

Budgeting

Create and analyse personal budgets, identify fixed and variable expenses, and calculate savings targets.

Worked examples

Calculating weekly surplus

Straightforward

Problem

Jade earns $1,100\$1{,}100 per week. Her weekly expenses are: rent $500\$500, groceries $110\$110, transport $75\$75, utilities $40\$40, and phone $25\$25. Calculate her weekly surplus.

Categorising expenses and calculating savings rate

Moderate

Problem

A household has a monthly income of $5,000\$5{,}000. Their monthly expenses include: rent $1,400\$1{,}400, car insurance $110\$110, health insurance $130\$130, internet $60\$60, phone $50\$50 (all fixed); groceries $450\$450, transport $180\$180, entertainment $220\$220, dining out $150\$150, clothing $100\$100, and personal care $150\$150 (all variable). Calculate the total fixed expenses, total variable expenses, and the monthly savings rate.

Saving an emergency fund

Challenging

Problem

Ryan earns $4,800\$4{,}800 per month. His total monthly expenses are $4,000\$4{,}000. He wants to build a 3-month emergency fund. How many months will it take at his current savings rate? If he also reduces his entertainment spending by $400\$400 per month, how many months will it then take?

Practise

Q1·Straightforward
Aisha earns $1,200\$1{,}200 per week. Her weekly expenses are: rent $550\$550, groceries $120\$120, transport $85\$85, utilities $45\$45, and phone $30\$30. Calculate her weekly surplus.
Q2·Straightforward
Calculate the total weekly expenses for a household with the following costs: rent $490\$490, food $135\$135, transport $80\$80, streaming subscriptions $25\$25, and gym membership $20\$20.
Q3·Straightforward
Ben earns $1,050\$1{,}050 per week. His total weekly expenses are $780\$780. Calculate his weekly surplus.
Q4·Straightforward
Chloe earns $1,450\$1{,}450 per week. Her weekly expenses are: mortgage $680\$680, utilities $90\$90, groceries $160\$160, transport $95\$95, phone $40\$40, and health insurance $55\$55. Calculate her weekly surplus.
Q5·Moderate
Daniel's monthly budget includes the following fixed expenses: rent $1,400\$1{,}400, phone $65\$65, internet $75\$75, car insurance $120\$120, and health insurance $95\$95. Calculate his total monthly fixed expenses.
Q6·Moderate
Emma has a monthly income of $5,200\$5{,}200. Her total monthly expenses are $4,160\$4{,}160. Calculate her monthly savings rate as a percentage of her income.
Q7·Moderate
A household budget has the following monthly categories: mortgage $1,850\$1{,}850 (fixed), groceries $560\$560 (necessary), dining out $420\$420 (discretionary), transport $200\$200 (mostly fixed), and streaming services $30\$30 (fixed). Which category has the most room for reduction without affecting essential needs?
Q8·Moderate
Calculate the total monthly variable expenses from the following budget items: groceries $420\$420, entertainment $180\$180, dining out $120\$120, clothing $85\$85, and personal care $65\$65.
Q9·Challenging
Priya earns $4,800\$4{,}800 per month. Her total monthly expenses are $3,600\$3{,}600. She wants to save a 3-month emergency fund. How many months will it take her to reach this goal?
Q10·Challenging
Liam earns $6,000\$6{,}000 per month. His fixed monthly expenses total $2,400\$2{,}400 and his variable monthly expenses total $1,600\$1{,}600. How many months will it take him to save a 3-month emergency fund?
Q11·Challenging
Mia has a monthly surplus of $800\$800 and wants to save a 3-month emergency fund of $9,600\$9{,}600. At her current rate this will take 12 months. Which single budget change would allow her to reach her goal in the fewest months?
Q12·Challenging
Noah's monthly income is $4,000\$4{,}000 and his total monthly expenses are $3,200\$3{,}200. If he reduces his entertainment spending by $160\$160 per month, how many months will it take him to save a 3-month emergency fund?