Pencil drawing of the Bitmain Antminer S21 Pro

Industrial Industrial (air) Rack / shelf Unknown

Bitmain Antminer S21 Pro

A popular air-cooled S21 sold in 220, 234 and 245 TH/s bins, all at 15 J/TH. It runs from a single-phase 220–277 V circuit and tolerates -20 to 45 °C air, but at 76 dBA it is far too loud for living spaces without a sound-proof enclosure.

Best price $2,199

$9.40 per TH · New · In stock at Altair Technology

Reviews from Nostr ↓

Hashrate234 TH/s worst 250 GH/sbest 1.16 PH/s 85th best of 197 (the bar uses a log scale)
Power (stock)3,510 W lowest 11 Whighest 22 kW 108th highest of 199 (the bar uses a log scale)
Efficiency15 J/TH worst 100 J/THbest 8.9 J/TH 53rd best of 195
Earns per kWh$0.101 worst $0.010best $0.171 54th best of 195
Heat output11,977 BTU/h worst 38 BTU/hbest 75,067 BTU/h 108th best of 199 (the bar uses a log scale)
Noise76 dB worst 76 dBbest 25 dB 62nd best of 68
Price per TH$9.40 worst $539.96best $1.82 44th best of 156 (the bar uses a log scale)

Where to buy

Store Trustpilot Condition Availability Listed price In your currency Per TH Checked Link
Altair Technology TrustScore 4.7 out of 5, 623 reviews New In stock $2,199 $2,199 $9.40 12 Nov 2026 Visit
Mineshop Ships from European Union TrustScore 4.7 out of 5, 1,610 reviews New In stock €2,000 excl. tax $2,225 $9.51 12 Nov 2026 Visit
Mining Wholesale Ships from Netherlands Ships out in 3-7 working days. Also 245 TH/s at EUR 2,299. Sold as "S21 Pro+". Price excl. VAT. TrustScore 4.7 out of 5, 401 reviews New In stock €2,199 excl. tax $2,447 $10.46 10 Nov 2026 Visit
Bitcoin Merch Ships from United States · 245 TH/s unit TrustScore 4.4 out of 5, 1,082 reviews Not stated In stock $2,700 $2,700 $11.02 4 Nov 2026 Visit
MiningStore Ships from United States Store notes TrustScore 3.4 out of 5, 5 reviews New In stock $3,030 $3,030 $12.95 4 Nov 2026 Visit
D-Central Ships from Canada Store notes No score Refurbished In stock CA$8,000 $5,620 $24.02 12 Nov 2026 Visit
Bitmain Official Shop Maker's own shop Store notes TrustScore 1.4 out of 5, 98 reviews New Out of stock $3,744 excl. tax $3,744 $16.00 4 Nov 2026 Visit
Compass Mining (hosted) Ships from United States Hosted: stays in a data centre Store notes TrustScore 3.3 out of 5, 790 reviews Used In stock $1,849 $1,849 $7.90 4 Nov 2026 Visit

Prices as listed on each store's page on the date shown, without shipping. Prices marked excl. tax leave out VAT or sales tax, and others may too. Per TH uses the hashrate of the unit each store sells. Converted at ECB rates of 11 Nov 2026. Trustpilot scores are for the store, not the device. Each store's name opens its page, with everything it sells and its reviews.

Heat, running cost and sats

Heat per day
—
Electricity per day
—
Mining earns per day*
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Net cost per day
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Net cost per kWh of heat
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Solo: chance of a block per year
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Earns per kWh, on 3-month averages
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Payback
—

*What a pool would pay on average at today's difficulty, block reward and bitcoin price, before pool fees. Solo miners usually earn nothing, and very rarely a whole block. A plain electric heater turns the same electricity into the same heat, so the mining income is what makes the difference.

Payback is how long the bitcoin a device earns takes to add up to its price. It leaves out electricity, which buys the heat: compare earnings per kWh with your electricity price to see whether mining alone covers it. It uses the average of the last 3 months, to 12 Nov 2026: bitcoin at $79,558, 969 EH/s on the network and 3.15 BTC a block, less a 2% pool fee, for the hours you set. It cuts the block subsidy in half at each halving, the next around Apr 2028, and otherwise assumes those carry on unchanged, which they won't. Income at today's difficulty and price is about 17% below that average. Hashrate usually rises, though miners that stop paying after a halving may switch off, which leaves more for the rest. How we work it out.

Specifications

BrandBitmain
ModelAntminer S21 Pro
SKU—
TypeIndustrial (air) · Industrial
Form factorRack / shelf
CoolingAir
Production statusUnknown *
Launch dateJul 2024 *
Hashrate234 TH/s
Power consumption (stock)3,510 W
Mining efficiency15 J/TH
ASIC chipBitmain BM1370 × 195 (reported by an independent source)
Heat output11,977 BTU/h
Input voltage220–277 V AC, single-phase
Frequency50–60 Hz
Net dimensions (W × D × H)219 × 450 × 293 mm (8.6 × 17.7 × 11.5 in)
Net weight18.5 kg (40.8 lb)
Noise76 dB
Operating temperature-20–45 °C (-4–113 °F)
Area heatedAbout 23–70 m² (our estimate)
Colours—
Company based inChina
Made in—

* Not confirmed by the maker's own documents yet.

Hashrate versions

VersionHashratePowerEfficiency
245 TH bin245 TH/s3,675 W15 J/TH
234 TH bin234 TH/s3,510 W15 J/TH
220 TH bin220 TH/s3,300 W15 J/TH

Features

  • Air cooling, up to 550 CFM airflow
  • Single-phase 220–277 V input, 20 A
  • Operating range -20 to 45 °C
  • RJ45 Ethernet 10/100M

Reviews

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Sources and data notes

Not yet confirmed from the maker's own documents: launch date; colours; where it's made; production status.

Spotted a mistake? Let us know.