Antminer S21: specs, earnings and solo odds
The Antminer S21 is Bitmain's air-cooled Bitcoin miner from the S21 generation. It is rated at 200 TH/s for 3500 W (17.5 joules per terahash).
Mining solo at today's difficulty, one Antminer S21 would expect to find a Bitcoin block about once every 96 years: a 1 in 35,000 chance on any given day.
- Hashrate
- 200 TH/s
- Power
- 3500 W
- Efficiency
- 17.5 J/TH
- Released
- Announced Oct 2023, first batch Jan 2024
What it earns a day
At today's difficulty of 140.58T and a block reward of 3.14838303 BTC, one Antminer S21 is expected to earn 9,011 sats a day on average (about $7.25 at a Bitcoin price of $80,408), read 27 Oct 2026 18:08 UTC. Running it uses 84 kWh a day.
| Power price | Electricity | Net a day |
|---|---|---|
| $0.05 per kWh | $4.20 | +$3.05 |
| $0.10 per kWh | $8.40 | −$1.15 |
| $0.15 per kWh | $12.60 | −$5.35 |
An average, not a wage. Solo mining pays this average out as a whole block or nothing: the figure is what the machine earns per day over a very long run, not what arrives each day. The machine's own price is not shown here. Open the calculator to use your own power price.
Checked specs
- Maker
- Bitmain
- Family
- Antminer S21
- Variant
- air-cooled
- Power input
- 220–277 V AC (one input wire, 20 A)
- Cooling
- Air
- Noise
- not published
- Released
- Announced Oct 2023, first batch Jan 2024
- At the maker
- Maker availability not checked
- Figures
- Figures from the maker's or designer's own pages (missing: noise)
| Mode | Hashrate | Power | J/TH |
|---|---|---|---|
| Rated | 200 TH/s | 3500 Wmaker's rating | 17.5 |
Sources (checked 2026-10-11): Bitmain spec. Image: Bitmain, from its product page. Background evened to white, trimmed, centred and resized by SoloLuck; the machine itself is not edited.
About the Antminer S21
At its rated 17.5 joules per terahash, the S21 needs about half the electricity of an Antminer S19 for the same work, and that is the whole story of a new mining generation. Announced in October 2023 and first shipped in January 2024, it was followed by the S21 Pro in March 2024 and, later, by the S23.
Like every air-cooled Antminer, it is built for a mining farm. It draws 3.5 kW from a 220 to 277 volt supply on a single 20 amp input, which in most homes means a dedicated circuit, and it turns all of that into heat around the clock. Bitmain publishes no noise figure for it; its sibling the S21 Pro is rated 76 dBA with the fans at full speed. Owners who run one at home usually give it its own circuit and a space where the noise and the heat do no harm, or some good in winter.
Solo, one S21 is a serious ticket by home standards, about as much hashrate as 165 Bitaxe Gammas in one box. The earnings table above shows how much its economics depend on the power price: the same machine can cover its electricity on average at one tariff and cost more to run than it is expected to earn at another.
On SoloLuck an S21 mines to its owner's own address with no fee, and a block it solves pays the whole reward straight to that address. Point it at the Lite port like any Antminer, or at the Pro port, which starts big machines at a higher share difficulty so their share feed settles at once.
Mine solo with it on SoloLuck
Point the Antminer S21 at SoloLuck with these three settings in its own web panel or app:
- Pool URL
stratum+tcp://stratum.sololuck.io:4334- Username
- your own Bitcoin address, optionally followed by a dot and a worker name (
bc1q….rig1) - Password
x(anything works)
Port 4334 is the Pro tier, for big ASICs, farms and rented hashrate (Braiins Hashpower) (min & start 1,048,576). Port 3333, the Lite tier the setup wizard uses for every ASIC, works too: its difficulty rises on its own to match the machine.
There is no fee and no account. If it solves a block, the network pays the whole reward straight to your address: SoloLuck never holds it. The setup wizard walks through it step by step.
Where to buy
No shop is linked for the Antminer S21 yet: we add one only after checking that it sells this exact model. The maker's own shop, or a reseller the maker lists, is the safest place to start.
Compare it
Also in the Antminer S21 family: Antminer S21 Pro, Antminer S21 XP, Antminer S21e XP Hyd., Antminer S21 XP Hyd., Antminer S21 XP+ Hyd., Antminer S21j XP Hyd., Antminer S21 XP Imm., Antminer S21+ Hyd., Antminer S21 Hyd., Antminer S21 Imm., Antminer S21+, Antminer S21e Hyd.. All hardware, with every model's figures and odds side by side.
How this page is paid for
The mining pool is free. Hardware referrals help support SoloLuck. The pool's fee is 0%, a found block pays the finder in full, and referral links have been on these pages since October 2026.
Links marked Referral link may earn SoloLuck a commission if you buy; links marked Plain link earn nothing. No shop can buy a spec, a place in a table, different odds or a better word from us. Specs come from the makers' and designers' own pages, linked next to each figure. How shops can work with us: Partners.
Quick answers
Can one Antminer S21 find a Bitcoin block on its own?
Yes: every hash is a fresh draw, so any miner can. At today's difficulty one Antminer S21 would expect a block about once every 96 years, a 1 in 35,000 chance on any given day, and most never find one.
How much does the Antminer S21 earn a day?
On average, about $7.25 a day at today's difficulty and Bitcoin price, before electricity. At $0.10 per kWh its power costs $8.40 a day, so it nets −$1.15. Solo mining pays that average as a whole block or nothing.
How do I solo mine with a Antminer S21?
Set the pool URL to stratum+tcp://stratum.sololuck.io:4334, the username to your own Bitcoin address (a dot and a worker name are optional) and the password to anything. SoloLuck charges no fee, and a block it finds pays the whole reward straight to your address.
How much power does the Antminer S21 use?
3500 W, by the figures linked on this page.