Let me paint you a dream you’ve probably seen online. You buy one shiny Bitcoin miner. You plug it in. It hums away in the corner of your garage, and a while later, you own a whole Bitcoin. Sounds almost too simple, right?
Good to see you, welcome back to Crypto Honest Reviews! 👋 Today I’m going to answer a question I see everywhere: how long does it actually take to mine 1 Bitcoin with an Antminer S21? I’ll warn you now, the answer made me read the numbers twice. Let’s go.
In This Guide
- The Short Answer
- Meet the Machine
- The Math, Step by Step
- What About Solo Mining?
- What It Costs in Electricity to Mine 1 Bitcoin
- What Could Speed It Up or Slow It Down
- Frequently Asked Questions
The Short Answer
About 26 years. That’s how long one Antminer S21, running nonstop in a pool at today’s network size, would take to earn a full Bitcoin. And that assumes nothing about the network ever changes, which has never once been true.
Meet the Machine
| Model | Bitmain Antminer S21 (200 TH/s version) |
| Hashrate | about 200 terahashes per second |
| Power use | about 3,500 watts (some listings say 3,550) |
| Efficiency | about 17.5 J/TH |
| Noise | about 75 decibels |
| Power supply | 220 to 240 volts |
| Price | listings in 2026 ranged from roughly $2,700 to $4,700 depending on seller |
The Math, Step by Step
- The network’s total power was estimated at about 860 EH/s in late August 2026 (ViaBTC). That’s 860,000,000 TH/s.
- Your S21’s share: 200 ÷ 860,000,000 ≈ 0.0000233%.
- The network pays out about 450 BTC a day in block rewards (144 blocks × 3.125 BTC).
- Your daily share: 450 × 0.000000233 ≈ 0.000105 BTC a day.
- Per month: about 0.0031 BTC. Per year: about 0.038 BTC.
- Time to 1 BTC: 1 ÷ 0.000105 ≈ 9,500 days, or about 26 years.
Transaction fees add a little to rewards, and pool fees take a little out, so treat 26 years as a solid estimate rather than a promise. Either way, you’re not close to one Bitcoin in a lifetime of casual mining. Even the machine’s own useful life is far shorter than 26 years.
What About Solo Mining?
Solo mining means keeping the whole block reward if you find a block, instead of sharing it with a pool. At the S21’s speed, the expected wait to find one block alone is more than 80 years. But “expected” is just an average. Solo miners with tiny machines really have found blocks, because mining is a lottery and every hash is a ticket. It’s possible, but it’s lottery math, not income math. The pool route above is the realistic one.
What It Costs in Electricity to Mine 1 Bitcoin
Here’s the number that really stopped me. If it takes about 9,500 days to mine a Bitcoin, and the S21 uses about 84 kWh a day, you burn about 800,000 kWh along the way. At different electricity prices:
| Electricity price | Power cost to mine 1 BTC | Compare to Bitcoin at $80,000 |
|---|---|---|
| 6¢/kWh (industrial) | about $48,000 | Profit |
| 10¢/kWh | about $80,000 | Break-even |
| 18.83¢/kWh (US average) | about $151,000 | Costs almost twice the coin’s value |
| 29.5¢/kWh (New York area) | about $237,000 | Costs about three times the coin’s value |
Read that table twice. At the average American electricity price, you’d spend roughly $151,000 in power to produce a Bitcoin worth $80,000. That’s why I keep saying the machine isn’t the expensive part. The electricity is. For the full picture, see my profitability guide.
What Could Speed It Up or Slow It Down
- More miners joining the network makes your share smaller and the wait longer.
- Miners leaving makes your share larger. Network power did fall from about 1.08 ZH/s in April to about 860 EH/s in late August, though that’s an estimate.
- The next halving, expected around 2028, cuts the block reward in half and roughly doubles the time again, unless the price rises to offset it.
- Newer, more efficient machines from competitors will keep making yours relatively slower.
Frequently Asked Questions
How many Bitcoin does an Antminer S21 mine per day?
Roughly 0.0001 BTC a day at today’s network size. That’s about $8 at an $80,000 Bitcoin, before electricity.
How long does it take to mine 1 Bitcoin with several machines?
It scales directly. Ten S21s would take around 2.6 years, but they’d also cost ten times the electricity. The profitability question stays the same.
Is it worth buying an S21 in 2026?
Only with very cheap electricity, roughly under 8 to 10 cents per kWh. At typical home rates it loses money, and buying Bitcoin directly gets you more for the same budget.
Can I mine a whole Bitcoin on a phone or laptop?
No, not in any practical sense. I covered this in mining on a laptop and in my guide on mining on a phone.
One last question for you: before you read this, how long did you think it would take? Tell me your guess in the comments. And if you know someone dreaming about buying a miner, send them this before they hit “buy.” Dream big, but check the math first. 🔢
Disclosure: Figures are estimates based on public specs and network data from mid-2026 and assume Bitcoin near $80,000, a network of about 860 EH/s, and constant conditions, which never hold in practice. I have no affiliate relationship with Bitmain or any seller. This article is for information only and is not financial advice.
