Belpex: the index that sets your electricity price

Belpex is Belgium's wholesale electricity price, set the day before for the next day on the EPEX SPOT exchange. If you have a variable or dynamic contract, your price per kWh flows directly from it, through a formula your supplier publishes. Here is how to read it, with real figures.

What exactly is Belpex?

An exchange price. Every day, generators, suppliers and traders bid for the electricity that will be delivered in Belgium the next day. The auction closes around noon and the result lands in the early afternoon: one price for each slot of the following day.

The name comes from Belgian Power Exchange, the Belgian market created in the mid-2000s and now part of EPEX SPOT. Since 1 October 2025, the day-ahead market no longer quotes the hour but the quarter hour. The price is expressed in euros per megawatt hour: 100 €/MWh equals 10 c€/kWh, before taxes, network costs and the supplier's margin.

Remember this above all: Belpex is not a tariff. It is the raw material of your tariff, before your supplier applies its coefficient, its margin and VAT, and before the distribution network operator (DSO, known in French as the GRD) adds its own bill.

How much is Belpex worth, month by month?

All three indices come from Mega's indexation page, consulted on 19 October 2026, where they are listed in €/kWh excluding VAT; we converted them to €/MWh and worked out the gaps. A note for careful readers: in places the page shows a "prices not yet available" label above tables that are in fact filled in, and its worked example mixes up two months. The values themselves do match the raw index: the May 2023 one repeats exactly the 80.18 €/MWh of the example.

The trend jumps out. After a quiet spring, monthly Belpex almost doubled between April and September, from 78.94 to 156.41 €/MWh, and the day of 19 October 2026 settled at a 221.97 €/MWh average according to the readings published by Belgian comparison sites. To put these figures in context, the annual averages they quote were 250 €/MWh in 2022, at the height of the crisis, then 99 in 2023, 69 in 2024 and 83 in 2025.

Belpex, Belpex RLP or Endex: which index does your contract follow?

The word "Belpex" actually hides several indices. Brugel, the Brussels energy regulator, sums it up in the methodology of its price simulator: each supplier chooses the parameter its contract follows, then sets the two coefficients of the formula itself. Here are the six families you come across on Belgian tariff sheets:

• Monthly Belpex, or monthly Epex: the arithmetic average of day-ahead prices over the delivery month. Cociter calls it BELIX.
• Belpex RLP: the same average, weighted by the real household consumption profile (Real Load Profile) published by Synergrid, the federation of Belgian grid operators. TotalEnergies used it for its Pixel offer in 2023.
• Belpex SPP: a weighting by the solar production profile (Synthetic Production Profile). It mainly serves to pay for solar panel injection.
• Quarterly Belpex: the three-month average, which Bolt applied in 2023 according to Infor GazElec.
• Endex: a forward price, quoted before the delivery month or quarter on ICE Endex. Engie's Easy offer was indexed on it in 2023.
• Quarter-hourly Belpex: the raw price of each quarter hour, reserved for dynamic contracts.

Why does RLP cost more than plain Belpex every month from January to September? Because a household consumes mostly in the morning and evening, when electricity is expensive, and little in the middle of the day, when solar output drags prices down. Weighting by that profile means paying the price of the hours when you actually consume. The gap reached 7.9 % in June, when sunny afternoons were pulling the average price down without helping the evenings. It fell back to 2.3 % in January, when the sun barely counts. Over nine months, the average RLP premium comes out at 5.2 %.

Infor GazElec, the independent Brussels energy information service, compared how these formulas evolved in Brussels: in 2023, the annual average of the index ranged from 93.36 €/MWh for Bolt to 157.55 €/MWh for Engie's Easy offer, indexed on Endex. Same year, same market, a 69 % gap before any margin is even applied.

How do you work out your price per kWh from Belpex?

Five steps, ten minutes, one calculator. Take your latest tariff sheet, the one attached to your contract or the one your supplier publishes every month.

1. Find the parameter. The sheet names the index: Belpex, Epex, BELIX, Belpex RLP, Endex. Note its frequency too, monthly or quarterly.
2. Note the two coefficients. The formula almost always takes the form (A × index) + B. At Mega, on a single-rate meter, A is 1.195 and B is 2.95 c€/kWh excluding VAT.
3. Look up the index value. For September 2026, monthly Belpex is 156.41 €/MWh, or 15.641 c€/kWh.
4. Apply the formula. 15.641 × 1.195 = 18.69, plus 2.95, giving 21.64 c€/kWh excluding VAT.
5. Add 6 % VAT. You get 22.94 c€/kWh for the energy component alone.

Scaled to 3,500 kWh, that September price amounts to about 803 € a year of energy, against 459 € at the April price. Network costs, taxes and the standing charge then come on top, identical whatever Belpex does.

Why does the same Belpex give two different prices?

Because coefficient A multiplies every market rise. It is the figure nobody looks at on a tariff sheet, yet it is the one that decides your bill when prices climb as they have this autumn. Let us compare Mega's single-rate formula with the one on Cociter's variable tariff sheet of January 2026, which applies (0.075 × BELIX + 5) c€/kWh, plus 6 % VAT.

Our own calculation, energy component only, 6 % VAT included, excluding standing charge and network costs. Every 10 €/MWh rise in Belpex adds 1.27 c€/kWh at Mega, or 44 € a year for 3,500 kWh, and 0.80 c€/kWh at Cociter, or 28 €. The tipping point sits at 46 €/MWh: below that level, Mega's formula becomes the cheaper of the two again, because its fixed part is smaller. At 2024's Belpex, with its 69 €/MWh average, the gap stayed modest; at this autumn's level, it exceeds 180 € a year.

Two caveats apply. The Cociter rate is reserved for cooperative members, which means buying a share, and its formula excludes the renewable energy contribution, billed separately. Mega imposes nothing of the kind. The comparison illustrates a mechanism; it does not name a winner for your household.

0.18 cents for a kWh fed into the grid in April

Belpex SPP tells the other side of the market. When every solar panel in the country produces at the same time, the wholesale price collapses, and a solar kWh is worth far less than an average kWh: in April 2026, 27.95 €/MWh against 78.94 for plain Belpex.

EnergyVision pays for injection with the formula 0.6 × Belpex SPP minus 15 €/MWh, according to its October 2026 tariff sheet. Applied to April's SPP, it gives 0.18 c€ per kWh injected. In September, with SPP back up to 100.53 €/MWh, the same kWh earns 4.53 c€.

A factor of twenty-five, with an identical formula.

Does Belpex change depending on your region?

No. Belgium forms a single price zone, so Belpex is the same in Liège, Ghent and Ixelles. Everything else, however, varies.

The offer, though, is not the same everywhere. A variable formula advertised in Wallonia does not necessarily exist in Brussels, and a Flemish household following Belpex quarter by quarter also pays for its power peak, whatever the market price. A prosumer still under the net-metering (compensation) scheme does not see SPP; one who is paid for injection feels it in full, and our article on the prosumer tariff sets out the rules region by region.

Belpex cannot be negotiated. The formula can. If your variable contract is coming to an end, reread its coefficient A, then compare the market's offers in our ranking of the best electricity suppliers and estimate your full bill with the simulator. For the underlying trade-off, our guide on fixed or variable covers the regional gaps, and the article on the dynamic tariff deals with contracts indexed per quarter hour. Finally, CREG, the federal electricity and gas regulator, describes the three contract families from its side.