Working out a realistic contents sum insured is about answering one question: how much would it cost to replace everything you own if your household contents were destroyed in a fire tomorrow?

In New Zealand, it's easy to underestimate this figure because we tend to think about what we paid for our belongings, rather than what it would cost to replace them with new items today.

The most reliable approach is to make a room-by-room inventory, estimate today's replacement prices, and add a sensible allowance for the things people often forget.

1. Work through your home room by room

Living room

• Sofa, armchairs and occasional furniture
• TV, speakers, gaming consoles and electronics
• Rugs, lamps, curtains and cushions
• Books, ornaments, artwork and decorations

Bedrooms and wardrobes

• Beds, mattresses, drawers and bedside tables
• Everyday clothing, coats, shoes and bags
• Bedding, towels and linen
• Jewellery, watches and accessories

Kitchen and laundry

• Fridge, freezer, microwave and other appliances
• Pots, pans, crockery, cutlery and glassware
• Kettle, toaster, coffee machine and air fryer
• Washing machine, dryer, vacuum cleaner and cleaning equipment

Office, hobbies and other spaces

• Computers, monitors, tablets and phones
• Desks, office chairs and printers
• Sports equipment, musical instruments and tools
• Children's toys, games, books and hobby equipment
• Garage, shed, outdoor furniture, bicycles and BBQ

A useful trick: imagine turning your house upside down. Everything that would fall out needs to be considered, including things in cupboards, drawers, the garage, the garden shed and the linen cupboard.

2. Use a New Zealand contents calculator

You don't have to price every teaspoon individually. Start with a calculator, then adjust the estimate to match what you actually own.

Here are three useful options:

NZI contents calculator

Estimates replacement values for your household and helps identify valuable items that may need separate cover.

Best for a structured starting estimate.

Use the NZI calculator

AMP contents calculator

Lets you adjust the estimated quantities and values of furniture, appliances, lawn equipment and other belongings.

Best for refining the estimate item by item.

Use the AMP calculator

Vero contents calculator

Provides an estimate based on your home, its rooms, household size and the quality and quantity of your possessions.

Best for cross-checking your first estimate.

Use the Vero calculator

These calculators provide estimates, not guarantees. Use the same household details in two calculators if you want to compare the results. Contents CalculatorEstimate Your Contents Value with Contents Insurance CalculatorHome Contents Calculator

3. Add the items people commonly underestimate

The small things can make a surprisingly large difference to the total.

• Clothing and shoes: Count everything across all household members, including winter coats, formalwear and sports shoes.
• Kitchen contents: Replacing all crockery, utensils, cookware, food containers and small appliances adds up quickly.
• Bedding and towels: Include duvets, pillows, sheets, blankets and spare sets.
• Technology: Include every phone, tablet, computer, monitor, gaming console, charger and accessory.
• Garage and outdoor items: Tools, bicycles, lawnmowers, garden equipment, outdoor furniture and barbecues.
• Stored and occasional-use items: Suitcases, Christmas decorations, camping gear, spare appliances and items in the attic or shed.

For expensive jewellery, artwork, watches, cameras, musical instruments or collectibles, check the policy's individual item limits. Some may need to be specified separately. House & Contents Insurance: Sum Insured ExplainedUnderstanding your contents sum insured

4. Build your own estimate

You can use this simple worksheet to organise your figures. Enter the combined new replacement cost for each category, rather than what you originally paid.

Amounts in NZ dollars (NZD)

Estimated contents replacement total

$0

Copy breakdownThis is a manual worksheet, not an insurance quote. Check whether your policy includes separately specified items in or outside the general contents sum insured, and whether its sum insured is defined inclusive or exclusive of GST.

5. Check your policy before settling on a figure

Three checks are particularly important in New Zealand:

1. Replacement cost versus present value. Some policies replace eligible items with new equivalents; others pay the present value of certain older items or categories. Your sum insured should reflect the cover you actually have. Contents CalculatorContents insurance calculator - Find your sum insured
2. Specified valuables. Check whether expensive individual items need to be listed separately, and whether their values count towards your general contents limit. Don't count them twice.
3. GST and policy wording. Don't automatically add or subtract GST. Different insurers describe their sums insured differently, so use the definition in your own policy documents.

Once you've calculated your total, compare it with the calculator estimates, correct any obvious omissions, and review the figure at renewal or after a major purchase. Consumer NZ also provides a useful house and contents insurance guide. House & Contents Insurance: Sum Insured ExplainedHow to get the best house and contents insurance

Let's narrow it down to your household

If you tell me a little about your home, I can help you arrive at a realistic ballpark figure without having to list every single possession.