United Kingdom household resilience
UK Government Prepare guidance recommends considering supplies for emergencies lasting a few days. Its water guidance cites a minimum 2.5–3 litres of drinking water per person per day, with around 10 litres per person per day providing greater comfort for basic cooking and hygiene.
For Great Britain, 105 connects you to the electricity network operator for a power cut. Northern Ireland uses different arrangements. During an incident, use official local information.
Use the global resilience check
The main calculator lets you combine electricity, gas/fuel, mains water, food-supply and communications disruptions, then compares your stored water, shelf-stable food and backup phone energy with the selected planning horizon.
Open the resilience calculator
What limiting resilience does — and does not — mean
The headline day figure identifies the earliest modelled resource limit in the selected scenario. The secondary 0–100 scenario score summarises broader coverage. Neither is a forecast of how long it is safe to remain at home, and neither replaces emergency services, public-health guidance, evacuation orders or professional advice.
Use the same plan in your preferred units
The global calculator keeps its country guidance pack separate from display units. You can use the automatic country default or switch water quantities between litres, US gallons and UK imperial gallons without changing the underlying planning target.
What the UK country pack changes
The UK planner keeps the 3 L/person/day baseline visible while also offering the approximately 10 L/person/day comfort figure described in government guidance. For power-cut planning, the dependency model is particularly relevant to gas boilers because the presence of gas does not necessarily mean the heating system can operate without electricity.
Use 105 in Great Britain for electricity-network information during a power cut, while recognising that Northern Ireland uses different arrangements. Local water companies, councils and emergency services remain the authoritative source during an incident.
What stays the same globally
The dependency engine, limiting-resilience calculation, device-load planner, food-usability logic, copy controls and printable plan use the same method in every supported country. Localisation changes the guidance source, water baseline, emergency references and default display units rather than creating a different product.