Bar shows the generation payment as a share of total yearly benefit. Estimates only; your FiT licensee’s statement is final.
Formula and breakdown
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This feed in tariff calculator estimates the yearly generation and export payments for an existing UK Feed-in Tariff (FiT) installation, compares deemed, metered and Smart Export Guarantee export, and projects what the remaining years could pay. It is for homeowners in Great Britain who already receive FiT payments, or who are buying a home with panels that came with a FiT.
Quick answer: A feed in tariff calculator multiplies your yearly generation by your generation tariff, then adds export at either 50% deemed (solar PV, 30 kW or less) or metered kWh. Example: 3,000 kWh at 16p plus 1,500 deemed kWh at 6p pays £570 a year. The scheme closed to new applicants on 1 April 2019.
What Is a Feed in Tariff Calculator?
A feed in tariff calculator is a tool that works out what the UK FiT scheme pays an accredited installation, from the kWh it generates, the kWh it exports and the tariff rates attached to it. In plain words: payment equals generation kWh times the generation tariff, plus export kWh (deemed or metered) times the export tariff.
According to Ofgem’s Feed-in Tariffs page, the scheme paid two things: generation payments for electricity produced and export payments for electricity sent to the grid, for between 10 and 25 years depending on technology, size and commissioning date. It closed to new applicants from 1 April 2019, but installations accredited before then continue to be paid for the rest of their term. Because every installation has its own tariff, set by technology, size and the date it joined, the feed in tariff calculator asks you to type the rates from your latest FiT statement rather than guessing them.
How Do You Use the Feed-in Tariff Calculator?
- Choose how your export is paid today: deemed, metered, or opted out to the Smart Export Guarantee (SEG).
- Enter your yearly generation in kWh from 12 months of generation meter readings.
- Copy the generation tariff and export tariff in pence per kWh from your FiT licensee statement.
- Pick the deemed export percentage: 50% for solar PV, wind, CHP and anaerobic digestion, or 75% for hydro.
- Enter the share of generation you actually export, from an export meter or smart meter if you have one, and an SEG rate to compare.
- Set your electricity unit price, an expected CPI rise and the number of FiT years left, and the feed in tariff calculator projects future payments.
How Are FiT Payments Calculated?
FiT payments equal generation kWh times your generation tariff plus export kWh times your export tariff, paid by your FiT licensee after you submit meter readings. With 3,000 kWh a year at an example 16p generation tariff, the feed in tariff calculator gives a generation payment of 3,000 x £0.16 = £480. Export at 50% deemed and an example 6p export tariff adds 1,500 x £0.06 = £90, a total of £570.
The generation payment is usually by far the larger part, because the export tariff is much lower. On top of the payments, every kWh you use in the home is a kWh you do not buy. At the Ofgem price cap of 26.32p per kWh for October to December 2026 (direct debit, GB average), using 1,800 kWh of your own solar saves about £474 a year. Our solar self-consumption calculator helps estimate how much of your generation you use at home.
What Is Deemed Export and Is It 50%?
For FiT year 17 (1 April 2026 to 31 March 2027), deemed export is 50% of the generation meter reading for solar PV, wind, combined heat and power and anaerobic digestion, and 75% for hydro. The government’s FiT determinations apply these figures to accredited installations of 30 kW or less where export is not measured by an export meter.
Deemed export pays the same whether you export a lot or a little. If your household uses most of its solar, perhaps because you are at home in the day, run a heat pump or charge an electric car, deemed export can pay for kWh you never sent to the grid. If you export more than half, metered export or the SEG may pay more. The table compares the three for 3,000 kWh a year with example rates of 6p FiT export and 12p SEG.
| Share actually exported | Deemed export (50%, 6p) | Metered FiT export (6p) | SEG export (example 12p) |
|---|---|---|---|
| 20% | £90 | £36 | £72 |
| 30% | £90 | £54 | £108 |
| 40% | £90 | £72 | £144 |
| 50% | £90 | £90 | £180 |
| 60% | £90 | £108 | £216 |
| 70% | £90 | £126 | £252 |
With these example rates, metered FiT export only beats deemed export above 50% export, while SEG at twice the FiT export rate beats it above 25%. The break-even moves with the rates, so run your own figures through the feed in tariff calculator. A battery changes the picture too, because it shifts solar from export to home use.
Do Feed-in Tariff Rates Rise With Inflation?
Yes: FiT tariff rates are adjusted every financial year in line with the Consumer Price Index from FIT year 17, which started on 1 April 2026. Ofgem’s tariffs and payments guidance explains that rates previously followed the Retail Price Index. The feed in tariff calculator applies your chosen CPI figure to the FiT generation and export payments for each remaining year, while an SEG rate is held flat because suppliers set and change those offers themselves.
The projection keeps generation constant. Real output varies with the weather each year and can fall slowly as panels age, so treat the lifetime figure as an estimate rather than a promise.
Should You Swap FiT Export for the Smart Export Guarantee?
Switching pays when your SEG rate times the kWh you really export is higher than your FiT export tariff times deemed (or metered) export, and you keep your FiT generation payments either way. Ofgem’s generator guidance says you must first opt out of FiT export payments with your FiT licensee before registering for the SEG, so check whether the change can be reversed before you act.
To see what the SEG alone would pay, try our Smart Export Guarantee calculator. If you are weighing a battery or other upgrade alongside the FiT, the solar payback calculator shows how long the extra spend takes to recover. Any change to meters, inverters or batteries must be carried out by a qualified installer, and in the UK electrical work must meet BS 7671.
Worked Example: Deemed Export Versus SEG
Example: a 3-bedroom semi-detached home with solar PV accredited for the FiT generates 3,000 kWh a year and exports about 40% according to its smart meter. Its statement shows an example generation tariff of 16p and export tariff of 6p, and an SEG offer of 12p is available. Eight FiT years remain.
- Generation payment: 3,000 x £0.16 = £480.
- Deemed export: 1,500 kWh x £0.06 = £90, so FiT payments total £570 a year.
- Metered export would be 1,200 kWh x £0.06 = £72; SEG export would be 1,200 x £0.12 = £144.
- Self-use: 1,800 kWh x £0.2632 = £473.76 off the electricity bill.
- With deemed export, total yearly benefit is £480 + £90 + £473.76 = £1,043.76.
- Over eight years at an example 3% CPI, FiT payments add up to about £570 x 8.892 = £5,068.63.
Here the feed in tariff calculator shows the SEG would pay £54 a year more than deemed export. The household would still need to compare the SEG supplier’s terms and confirm the opt-out process with its FiT licensee before switching.
Frequently Asked Questions
Can I still apply for the Feed-in Tariff?
No. Ofgem confirms the FiT scheme closed to new applicants from 1 April 2019, apart from limited grace period cases. Installations accredited before then keep their payments for the rest of their term. New solar owners can earn for exported electricity through the Smart Export Guarantee instead.
How are FiT payments calculated?
Your FiT licensee multiplies the kWh on your generation meter by your generation tariff, then pays export either on metered export kWh or on deemed export. For solar PV of 30 kW or less without an export meter, deemed export is 50% of generation for FiT year 17.
What is deemed export on the Feed-in Tariff?
Deemed export is an estimate used when no export meter records what you send to the grid. The government’s year 17 determination sets it at 50% of the generation meter reading for solar PV, wind, CHP and anaerobic digestion, and 75% for hydro, for installations of 30 kW or less.
Do FiT rates go up with inflation?
Yes. Ofgem says FiT tariff rates are adjusted each financial year in line with the Consumer Price Index from FIT year 17, which began on 1 April 2026. Before that, rates followed the Retail Price Index. Enter an expected CPI figure to project future payments.
Should I switch FiT export payments to the Smart Export Guarantee?
It can pay more if your SEG rate times the kWh you really export is higher than your FiT export tariff times deemed export. You keep generation payments either way. Ofgem says you must first opt out of FiT export with your FiT licensee, so compare carefully before switching.
What happens to my FiT if I sell my house?
The payments stay with the installation, so the new owner can take them on. For a typical MCS-certified home system, contact the FiT licensee, who updates the generator details on the Central FiT Register. Mention the FiT in the sale documents so buyers know what comes with the property.
Checked October 2026 by the Solaxyra Editorial Team. Sources: Ofgem: Feed-in Tariffs, Ofgem: FIT tariffs and payments, GOV.UK: FiT determinations Year 17, Ofgem: FIT generators, Ofgem: price cap October to December 2026.