Why Convert kWh to Therms?

UK domestic gas bills have been denominated in kilowatt hours (kWh) since 1999. However, converting kWh to therms is useful in several real-world scenarios: comparing your consumption against US appliance ratings or energy benchmarks, working with M&E engineers specifying US-manufactured heating equipment, reviewing commercial energy contracts that reference therms or dekatherms, and cross-referencing energy audit data from international sources.

0.034121
therms
1 kWh in therms
34.121
therms
1,000 kWh in therms
392.5
therms
UK avg/year (11,500 kWh)
3,412
BTU
1 kWh in BTU

The kWh to Therms Formula

This is the exact reverse of the therms-to-kWh conversion. Both kWh and therms are energy units, so the relationship between them is a fixed mathematical constant — no calorific value, volume correction factor or regional data is required.

⚡ kWh to Therms Formula
therms = kWh ÷ 29.3001
÷ 29.3001Exact conversion factor — always fixed
= × 0.034121Equivalent multiplication form
÷ 293.001Gives dekatherms (Dth) instead
× 3,412.14Gives BTU instead

How to Convert kWh to Therms — Step by Step

1

Find Your kWh Value

Locate the kWh figure on your UK gas bill — it may be labelled "energy used", "consumption (kWh)" or "units". Smart meter apps and in-home displays also show kWh. For annual consumption, add up all monthly or quarterly bills, or use a 12-month meter reading.

UK bill example: "Gas consumption: 958 kWh" Annual total: "Total this year: 11,500 kWh"
2

Divide by 29.3001

Divide the kWh value by 29.3001 to get therms. You can also multiply by 0.034121 — both give the same result. For dekatherms (Dth), divide by 293.001 instead.

11,500 kWh ÷ 29.3001 = 392.5 therms 11,500 kWh ÷ 293.001 = 39.25 Dth 958 kWh ÷ 29.3001 = 32.7 therms/month
Quick check: 1,000 kWh ≈ 34.1 therms. Use this to sense-check large conversions.
3

Interpret Your Result

Compare your therms result against relevant benchmarks. For US household comparison: a typical American home uses 500–700 therms/year. For commercial contracts: most UK Dth contracts specify daily quantities (Dth/day). For appliance ratings: US boiler output is often quoted in BTU/hour or therms/hour.

UK avg home: 392.5 therms/year (11,500 kWh) US avg home: ~600 therms/year (~17,580 kWh) 1 Dth/day: ~10.2 kWh/hour continuous flow

Worked Examples

Monthly Low
175 kWh (summer)
5.97 therms
175 ÷ 29.3001 = 5.97 therms
≈ 0.597 Dth
Monthly Average
958 kWh
32.70 therms
958 ÷ 29.3001 = 32.70 therms
UK avg monthly
Monthly Winter
1,800 kWh (Jan)
61.43 therms
1800 ÷ 29.3001 = 61.43 therms
≈ 6.14 Dth
Annual Low
8,000 kWh
272.9 therms
8000 ÷ 29.3001 = 272.9 therms
Ofgem low benchmark
Annual UK Average
11,500 kWh
392.5 therms
11500 ÷ 29.3001 = 392.5 therms
Ofgem medium 2026
Annual High
17,000 kWh
580.3 therms
17000 ÷ 29.3001 = 580.3 therms
Ofgem high benchmark

kWh to Therms Conversion Table 2026

Full reference table for converting kWh to therms and dekatherms. Highlights show Ofgem consumption benchmarks. For the reverse, see our therms to kWh converter.

kWhThermsDekatherms (Dth)BTUMJEquiv. m³ (CV 39.5)
10.034120.0034123,4123.6000.089 m³
100.34120.0341234,12036.000.894 m³
501.7060.1706170,600180.04.47 m³
1003.4120.3412341,200360.08.94 m³
2508.5310.8531853,100900.022.4 m³
50017.061.7061,706,0001,80044.7 m³
958 (UK avg/month)32.703.2703,269,0003,44985.7 m³
1,00034.123.4123,412,0003,60089.4 m³
2,00068.246.8246,824,0007,200178.9 m³
5,000170.617.0617,060,00018,000447.3 m³
8,000 (Ofgem low)272.927.2927,290,00028,800715.7 m³
11,500 (Ofgem medium)392.539.25392,500,00041,4001,029 m³
15,000511.851.18511,800,00054,0001,342 m³
17,000 (Ofgem high)580.358.03580,300,00061,2001,521 m³
20,000682.568.25682,500,00072,0001,789 m³
50,0001,706170.61,706,000,000180,0004,473 m³

m³ equivalent uses CV 39.5 kWh/m³, VCF 1.02264. Ofgem benchmarks highlighted. Source: Ofgem TDCVs 2026.

UK vs US Gas Consumption in Therms — 2026

Converting UK kWh to therms lets you meaningfully compare British and American household gas consumption. The difference is striking: US homes are generally larger, less well insulated, and often use gas for clothes drying and air conditioning backup heating — resulting in roughly 50–70% higher gas use than the UK average.

🇬🇧 UK Benchmarks (Ofgem 2026)

Low household273 therms/yr
Medium (average)392 therms/yr
High household580 therms/yr
Monthly average32.7 therms/mo
Daily average1.07 therms/day

🇺🇸 US Benchmarks (EIA 2026)

Low household~350 therms/yr
Medium (average)~600 therms/yr
High household~900+ therms/yr
Monthly average~50 therms/mo
Daily average~1.64 therms/day

🔥 Need the Reverse? Convert Therms Back to kWh

Use our therms to kWh converter — or see your full UK gas usage breakdown with our usage calculator.

UK Regional Calorific Values 2026

If you also need to convert your therms result into approximate gas volume (m³), the table below shows regional UK calorific values for 2026. Use the mid-range CV for your region to estimate how many cubic metres correspond to your kWh or therms figure.

UK RegionCV Range (kWh/m³)BandkWh per m³Therms per m³
🇬🇧 UK National Average38.5 – 40.5Average≈ 11.18 kWh≈ 0.381 therms
London & South East39.0 – 41.5Above Avg≈ 11.44 kWh≈ 0.390 therms
South West England38.8 – 41.0Average≈ 11.34 kWh≈ 0.387 therms
East Midlands39.0 – 40.8Average≈ 11.34 kWh≈ 0.387 therms
West Midlands38.5 – 40.5Average≈ 11.18 kWh≈ 0.381 therms
Yorkshire & Humber38.0 – 40.2Average≈ 11.11 kWh≈ 0.379 therms
North West England37.8 – 40.0Below Avg≈ 11.06 kWh≈ 0.377 therms
North East England37.5 – 39.8Below Avg≈ 10.98 kWh≈ 0.374 therms
Scotland37.2 – 40.0Below Avg≈ 11.01 kWh≈ 0.376 therms
Wales38.0 – 40.2Average≈ 11.11 kWh≈ 0.379 therms

Therms/m³ = (CV × 1.02264 ÷ 3.6) ÷ 29.3001. Mid-range regional CV used. Source: National Grid / Xoserve 2026.

Frequently Asked Questions

How many therms is 1 kWh?
1 kWh = 0.034121 therms (exactly 1 ÷ 29.3001). This is a fixed mathematical relationship between two energy units — it never changes regardless of gas type, region or supplier. To convert any kWh to therms, divide by 29.3001. Use the converter above for any value.
How do I convert kWh to therms?
Divide your kWh value by 29.3001. Equivalently, multiply by 0.034121. Formula: therms = kWh ÷ 29.3001. Key examples: 1,000 kWh = 34.12 therms; 11,500 kWh = 392.5 therms; 17,000 kWh = 580.3 therms. For dekatherms, divide by 293.001 instead.
How many therms does a UK home use per year?
Converting Ofgem's 2026 benchmarks: Low = 273 therms/year (8,000 kWh); Medium/average = 392.5 therms/year (11,500 kWh); High = 580 therms/year (17,000 kWh). For a monthly average, divide by 12: the UK average works out to ~32.7 therms/month.
Why would I convert kWh to therms?
Common reasons include: comparing your UK bill against US household benchmarks; specifying or comparing US-manufactured heating equipment rated in BTU/hr or therms/hr; commercial UK gas contracts priced in p/therm; international energy benchmarking; and energy auditing across UK and US building standards. UK domestic consumers rarely need therms day-to-day — kWh is the standard UK billing unit.
How many therms is 1,000 kWh?
1,000 kWh = 34.12 therms (1,000 ÷ 29.3001 = 34.121). Other key conversions: 500 kWh = 17.06 therms; 2,000 kWh = 68.24 therms; 5,000 kWh = 170.6 therms; 10,000 kWh = 341.2 therms; 11,500 kWh (UK avg) = 392.5 therms. Full table is above.
What is a dekatherm (Dth) and how do I convert kWh to Dth?
A dekatherm (Dth) = 10 therms = 293.001 kWh. To convert kWh to dekatherms, divide by 293.001. The UK annual average of 11,500 kWh = 39.25 Dth. Dekatherms are used in commercial and wholesale gas contracts — most UK Dth pricing is for daily flow rates (Dth/day).
Does the kWh to therms conversion depend on calorific value?
No. Both kWh and therms are energy units — their conversion is a fixed constant (1 kWh = 0.034121 therms) that never changes. Calorific value only comes into play when converting gas volume (m³ or ft³) to energy. If you need to convert a UK meter reading to therms, first convert m³ to kWh using our M3 to kWh calculator, then divide by 29.3001.
How do I convert kilowatts (kW) to therms per hour?
Divide kW by 29.3001 to get therms/hour. Example: 100 kW ÷ 29.3001 = 3.413 therms/hour. This is because 1 kW = 1 kWh/hour, so the same conversion factor applies to power as to energy. Used when comparing UK (kW) rated boilers and heating plant against US (therms/hr) specifications.