Antminer S21 Profitability Guide: Why These Miners Are Still Worth It in 2025
Antminer S21 Profitability in 2025: Are These Miners Still Worth It?
The Bitmain Antminer S21 series remains one of the most profitable ASIC miners on the market in 2025. Even with the newer S23 generation available, the S21 lineup — including the Antminer S21 Pro, S21 Hyd, and S21 XP Hyd — delivers exceptional hashrate-per-dollar value. At CaptainMining, we offer these miners for sale and provide professional hosting at just $0.10 CAD/kWh, making Antminer S21 profitability even more attractive for Canadian miners.
Complete Antminer S21 Model Lineup & Specs
Bitmain's S21 series includes multiple variants designed for different mining setups. Here is a complete comparison of every Antminer S21 model and their key specifications:
| Model | Hashrate | Power | Efficiency (J/TH) | Cooling |
|---|---|---|---|---|
| Antminer S21 | 200 TH/s | 3,550W | 17.5 J/TH | Air |
| Antminer S21 Pro | 234 TH/s | 3,531W | 15.0 J/TH | Air |
| Antminer S21 XP | 270 TH/s | 3,645W | 13.5 J/TH | Air |
| Antminer S21 Hyd | 335 TH/s | 5,360W | 16.0 J/TH | Hydro |
| Antminer S21e XP Hyd 3U | 860 TH/s | 11,180W | 13.0 J/TH | Hydro |
Antminer S21 Profitability Breakdown at $0.10/kWh
Electricity cost is the most important factor in Bitcoin mining profitability. At CaptainMining's hosting rate of $0.10 CAD per kWh, here is what you can expect from each S21 model in terms of daily revenue and ROI timeline (estimates based on current BTC price and difficulty — these change frequently):
| Model | Daily Revenue (est.) | Daily Power Cost | Daily Profit (est.) | Approx. Price |
|---|---|---|---|---|
| S21 (200 TH/s) | Varies with BTC | ~$8.52 | Varies | Contact us |
| S21 Pro (234 TH/s) | Varies with BTC | ~$8.47 | Varies | Contact us |
| S21 XP (270 TH/s) | Varies with BTC | ~$8.75 | Varies | Contact us |
| S21 Hyd (335 TH/s) | Varies with BTC | ~$12.86 | Varies | Contact us |
Note: CaptainMining does not provide financial or investment advice. Mining revenue fluctuates based on Bitcoin price, network difficulty, and transaction fees. Always do your own research before investing in mining hardware.
Why Antminer S21 Pro Profitability Stands Out
The Antminer S21 Pro is arguably the sweet spot of the entire S21 lineup. With 234 TH/s and an efficiency of just 15.0 J/TH, it delivers more hashrate than the standard S21 while consuming nearly the same power. This makes the S21 Pro profitability particularly compelling for miners looking for the best balance of performance and operating costs. At $0.10/kWh hosting, the S21 Pro offers one of the lowest cost-per-terahash figures in Bitcoin mining today.
Antminer S21 XP 270TH Profitability: Maximum Air-Cooled Performance
For miners who want the highest hashrate possible in an air-cooled unit, the Antminer S21 XP is the top choice. At 270 TH/s with 13.5 J/TH efficiency, the Antminer S21 XP 270TH profitability is outstanding. This model pushes air-cooled Bitcoin mining to its limits, and when paired with our low-cost hosting in Canada, it becomes an extremely competitive mining solution.
Antminer S21 Hydro Profitability: Higher Hashrate with Water Cooling
The Antminer S21 Hyd (335 TH/s) takes profitability to another level thanks to hydro cooling technology. Water-cooled miners run more efficiently and quietly, which makes them ideal for large-scale operations. The Antminer S21 hydro profitability benefits from higher hashrate output per unit, though the infrastructure requirements (coolant loops, radiators) mean most miners prefer professional hosting solutions.
CaptainMining offers dedicated hydro ASIC hosting for water-cooled miners like the S21 Hyd, so you can maximize your returns without building cooling infrastructure at home.
S21 vs S23: Should You Wait for the Newest Generation?
Bitmain's Antminer S23 series offers improved efficiency, but the S21 series remains highly profitable for several reasons:
- Lower purchase price: S21 models are now available at reduced prices compared to launch, offering better ROI potential
- Proven reliability: The S21 has been running in mining farms worldwide since 2024 with a strong track record
- Immediate availability: S21 units ship immediately while S23 models may have longer lead times
- Still efficient: At 13.5–17.5 J/TH, the S21 lineup remains competitive with most miners on the market
How to Maximize Your Antminer S21 Mining Profits
Getting the best return from your Bitmain Antminer S21 requires optimizing several factors beyond just buying the hardware:
1. Choose Low-Cost Electricity
Electricity is your largest ongoing expense. CaptainMining's hosting at $0.10 CAD/kWh in Canada is among the most competitive rates available. Learn more about our hosting service.
2. Select the Right Mining Pool
Choose a mining pool with low fees and reliable payouts. Popular options include Foundry USA, Braiins Pool, and ViaBTC. Our Antminer setup guide walks you through pool configuration.
3. Monitor and Maintain Your Hardware
Regular maintenance, firmware updates, and monitoring keep your S21 running at peak efficiency. Hosted miners at CaptainMining receive 24/7 professional monitoring.
4. Consider Earning Bitcoin Rewards with Shakepay
While your miners work, you can earn additional Bitcoin rewards through Shakepay — a Canadian crypto platform that lets you shake your phone daily to earn free Bitcoin. Use referral code 8K3RGZD to get a bonus.
Frequently Asked Questions
Is the Antminer S21 still profitable in 2025?
Yes. The Antminer S21 series remains profitable in 2025, especially when paired with low-cost electricity. At $0.10 CAD/kWh, all S21 models generate positive returns at current Bitcoin prices. However, profitability varies with BTC price and network difficulty.
Which Antminer S21 model is most profitable?
The Antminer S21 XP (270 TH/s) offers the best efficiency at 13.5 J/TH for air-cooled mining, while the S21 Hyd (335 TH/s) provides the highest total hashrate. The S21 Pro offers the best balance of price and performance.
How much does it cost to run an Antminer S21 per day?
At $0.10 CAD/kWh, the standard S21 costs approximately $8.52 CAD per day in electricity. The S21 Pro costs about $8.47/day, and the S21 XP costs about $8.75/day.
Is it better to mine at home or use hosting?
Professional hosting is recommended for most miners. Home mining requires dealing with noise (75+ dB), heat, and high residential electricity rates. Hosting at CaptainMining provides low electricity rates, 24/7 monitoring, and professional maintenance. Read our full comparison.
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Disclaimer: CaptainMining does not provide financial or investment advice. Mining profitability depends on Bitcoin price, network difficulty, electricity costs, and hardware performance — all of which fluctuate. Past performance does not guarantee future results. Always conduct your own research before making investment decisions.