The bill went up. The question is why.
Every app shows that the electricity bill rose by three euros. None of them says whether that was consumption or the price per kWh — and the answer changes what you do next. Navefi keeps the quantity behind each bill and splits the two effects to the cent.
Electricity
Gas
Fuel
fuel · versus June 2026
€8.70 less
You used less, but the price moved against you.
The two halves add up to the whole difference. There is no remainder.
Consumption and price, split inside one bill
The difference between two months is broken into two parts — how much came from using more or less, how much came from the unit price — and the two add back to exactly the change in the bill.
Electricity, gas and fuel
kWh, cubic metres and litres. Each kind stays in its own unit: litres of diesel expressed in kilowatt hours is technically correct and answers a question nobody is asking.
The unit price is derived, not typed
Record the reading and Navefi divides it into the bill that paid for it. There is no tariff field to maintain, and therefore no tariff field to go stale.
260 kWhJuly 2026 · paid 2 August€58.40
15 m³July 2026 · paid 8 August€18.20
A bill belongs to the month before it was paid
The electricity you pay in August is July’s consumption. Navefi books the reading in the month it was used, not the month the money left — otherwise every month lands in the wrong column.
A reading lives attached to the expense that paid it
With no expense there is no unit price, and a reading with no expense is not kept. That is what stops the history filling up with numbers that have no money behind them.
Predicted monthly
Paid this month
Upcoming€242.20
- Crédito automóvelMonthly · Transport€186.00Due tomorrow
- Águas de LisboaMonthly · Utilities~€21.70est.Due in 3 days
- Seguro automóvelMonthly · Transport€34.50Due in 10 days
A tank of diesel is not a meter: it is a moment, not a period. Navefi treats the two differently — fuel compares fill to fill, electricity and gas compare month to month.
Frequently asked questions
Do I have to type the kWh by hand?
The quantity, yes, once per bill — it is the one number a bank cannot tell you. The statement carries the amount paid; the quantity is on the utility bill or the pump receipt. Without it there is no unit price and nothing to separate.
Does it work with a two-rate tariff?
Navefi divides the bill total by the total quantity, so the price it shows is the average price actually paid that month. That is the one that matters for comparing months: it folds tariff, standing charge and taxes into a single measure.
What if I change supplier?
The comparison is between months, not between contracts. A switch shows up as what it is — a step in the unit price — and Navefi tells you how much of that step reached your bill.
The fastest way to understand it is to use it
Start free, or book twenty minutes with us and we show this with your bank and your kind of income.
