This is how you can find out exactly how long your supplies would last in an emergency

Households across the UK have been urged to keep an “emergency kit” including supplies of cash, bottled water and tinned food at home amid a growing threat of severe weather or war.

Defence secretary Wes Streeting warned households are increasingly likely to be hit by fires, floods, and enemy attacks, including cyber warfare. It comes as the government turns its focus to national resilience in the wake of threats from Russia and severe weather, including back-to-back heatwaves and significant droughts over the summer.

It has advised people to put together an emergency kit including a torch, charged power bank, first aid kit, non-perishable food supplies, and bottled water, which could be used in the case of power failure or a disruption to your water supply.

But keeping and maintaining an emergency stock of food and water can be difficult, with many people simply storing a few cans and forgetting to check expiry. Even the most organised of preppers can find it challenging to keep track of supplies without complex spreadsheets or rotation systems.

It was under these circumstances that father-of-two Dominic Brooks, 34, decided to create a calculator to help people stay on top of their emergency supplies.

“I first started keeping my emergency kit when I became a dad,” he explained. “I have two young daughters, so it falls on me to prepare for an emergency situation.

“I don’t want to have my girls going without because I failed to think ahead.”

Mr Brooks began collecting tinned food, bottled water, and rice, as well as a small camping stove and fuel in case of a power cut. He created a spreadsheet to keep track of the expiry dates of his supplies, but soon realised the administrative burden of keeping it updated.

“I’m a big guy for spreadsheets, but I was getting pretty bored of updating the dates cell by cell,” he said. The idea for his app Provision was then born.

The app allows you to input the number of people in your household and the supplies you have, and calculates exactly how long you would be prepared for in the event of an emergency.

It takes into consideration government and NHS guidance on nutrition, water consumption, and the fuel needed to cook any food, and gives an estimated number of days your stocks would last. If you are missing one essential - for example bottled water - the total would be zero, despite any other supplies you may have.

He said he spent time trying to consider “every scenario” in his preparation, and believes the app can help households become better prepared for any situation that may arise.

“Water does tend to run out first, and fuel is another thing people forget about,” he said. “You can calculate how long your stores will last cooking with gas, and then again if the mains power turns off.”

Mr Brooks said that despite the “doomsday” attitude of some preppers, he wants his app to help ordinary families prepare for realistic scenarios of power cuts, storms, floods, and other emergencies.

“I don’t want this to be a doomsday app,” he said. “I wanted it to be a nice calculator that you can use to help yourself, for free.”

The app is currently available on the web and Play Store, and has been submitted to Apple’s App Store for approval.