Money calculators

Money questions that come up every week: what a discount really saves after GST, which pack is cheaper per gram, what gold or silver costs today, and how far your savings would stretch. Each tool shows the formula, so you can check the shop's figure yourself.

Gold, silver and currency start with a live market rate, cached for an hour or so. The rate is a starting point: type the rate on your bill or your jeweller's board for an exact figure.

• Currency converter: You need today's exchange rate between two currencies.
• Gold value: You are buying or selling gold jewellery.
• Silver value: You are pricing silver to buy or sell.
• Discount: You want the sale price, or stacked discounts like 20% + 10%.
• Discount with GST: Final price after discount and GST.
• Unit price: Which pack is cheaper per kg or litre.
• Profit margin: You price goods and need margin against markup.
• Markup: You want a selling price from your cost and markup, with the margin it gives.
• Rent split: You want a fair rent split between roommates or a couple.
• Fuel cost: You want a trip or monthly fuel cost, or petrol against EV.
• Electricity bill: You want to know which appliances drive your bill.
• Net worth: You want your net worth from what you own and what you owe.
• Emergency fund: You want to know how big your emergency fund should be and how long it takes.