Somebody on Reddit had two hundred to spend and one useful fact: they pay 13.5 cents a kilowatt-hour. That second number decides far more than the first. There is a single electricity price at which every mining machine stops working, it can be calculated exactly, and once you know yours the whole catalogue sorts itself out.
- ✓Every miner has a break-even electricity price: the rate at which it earns exactly what it burns.
- ✓That price depends on just two things — the machine’s efficiency, and current mining conditions.
- ✓The formula is short enough to do on a phone, and it is in this article.
- ✓At a typical household rate, most older hardware is already below the line.
- ✓Rising difficulty pushes every break-even price down over time, so always buy headroom.
The one number that decides everything
Mining income is simple. A machine produces a certain amount of Bitcoin per day, and burns a certain amount of electricity per day. If the Bitcoin is worth more than the electricity, you are ahead. If not, you are paying to run a heater.
The exact electricity price where those two are equal is the break-even rate. Below it, the machine works. Above it, it does not.
A calculator gives you a number for today. A break-even rate tells you how much room you have before the machine stops working at all. One is a snapshot; the other is a margin of safety. When conditions change — and they always do — the margin is what saves you.
The formula, done slowly
Three steps, with a real machine. We will use the Antminer S21.
Every machine, ranked
| Miner | Hash rate | Power | J/TH | Gross per day | Break-even rate |
|---|---|---|---|---|---|
 Antminer S19k Pro - 110 TH/s |
110 TH/s | 2,530 W | 23.00 | $4.42 | $0.0728 |
 Antminer S21 - 188 TH/s |
188 TH/s | 3,290 W | 17.50 | $7.55 | $0.0957 |
 Antminer S21 Pro - 245 TH/s |
245 TH/s | 3,675 W | 15.00 | $9.84 | $0.1116 |
 Antminer S21+ Hyd - 395 TH/s |
395 TH/s | 5,925 W | 15.00 | $15.87 | $0.1116 |
 Whatsminer M79S - 1.35 PH/s |
1,350 TH/s | 20,000 W | 14.81 | $54.24 | $0.1130 |
 WhatsMiner M73S - 560TH/s |
560 TH/s | 7,560 W | 13.50 | $22.50 | $0.1240 |
 Antminer S23 - 318 TH/s |
318 TH/s | 3,498 W | 11.00 | $12.78 | $0.1522 |
 Antminer S23 Hyd - 580 TH/s |
580 TH/s | 5,510 W | 9.50 | $23.30 | $0.1762 |
What your own rate rules in and out
First, get your real rate. Take a bill, divide the total amount by the units used. That includes standing charges and tax, which the advertised tariff usually does not. Then find your band below.
| Your electricity rate | What it means for mining | What to do |
|---|---|---|
| Under $0.05 / kWh | Everything in the catalogue works, including older hardware. | Choose on price and reliability. You have the widest choice of anyone. |
| $0.05 – $0.09 / kWh | Most current machines work. The oldest are marginal. | Buy current-generation hardware and you have comfortable headroom. |
| $0.10 – $0.15 / kWh | Only efficient machines clear the line, and not by much. | Buy the best efficiency you can afford, or host. Do not buy older hardware. |
| $0.16 – $0.25 / kWh | Almost nothing works at home on current conditions. | Hosting is the realistic route, or treat a small machine as a hobby. |
| Over $0.25 / kWh | Home mining does not clear its own running cost. | Host the hardware, or use a miner as a heater where the heat has real value. |
The middle row, highlighted, is where most people in developed countries actually sit. It is the uncomfortable band: mining is possible but the margin is thin, and a single difficulty rise can erase it. That is the band where hosting stops being a convenience and starts being the arithmetic.
For comparison, the OneMiners hosting network averages $0.0480 per kWh on seven-year fixed rates, with the cheapest active site at $0.0364 — which places every machine in the table above comfortably in the green, with room left over.
Why the line moves against you
Break-even rates are not permanent. Two forces push them around, and over the long run one of them mostly pushes down.
- Bitcoin price up, break-even up. The same machine produces the same Bitcoin, but each unit is worth more, so it can afford dearer electricity.
- Difficulty up, break-even down. More competition means less Bitcoin per machine per day, so it can afford less.
What a small budget actually buys
Back to the Reddit poster: two hundred to spend, at 13.5 cents a kilowatt-hour. Here is the honest answer to that specific question.
- 1At 13.5 cents, cheap old hardware is the worst possible choice. The machines that fit a small budget are exactly the machines with the highest J/TH, and those are the ones furthest below the line in Chart 1.
- 2A small solo or hobby device is a legitimate use of that money. It will not pay for itself, but it is honest, low power, and genuinely interesting.
- 3Saving until you can buy efficiency is usually better. One current-generation machine beats three old ones at the same total price, at almost any electricity rate.
- 4Or change the rate instead of the machine. The rate is a bigger lever than the hardware. Moving from 13.5 cents to a fixed industrial rate does more for the maths than any purchase in that budget.
Revenue is set by the network. Efficiency is set by the machine. Electricity is the only part you get to choose — which is why it decides almost everything.
The most forgiving machines in the catalogue
Every listing publishes hash rate and wattage, so you can run the break-even formula yourself before you buy anything.
Browse Bitcoin minersCompare fixed power ratesQuestions people keep asking
Where these numbers come from
- Miner hash rate, wattage and price: live OneMiners catalogue, 27 August 2026.
- Bitcoin price $79,264 and network hash rate 887.8 EH/s: CoinGecko and mempool.space, 27 August 2026.
- All revenue figures are block subsidy only (3.125 BTC per block, 144 blocks per day), before transaction fees and pool fees.
- Difficulty scenarios in Chart 2 scale today’s revenue inversely with difficulty, holding the Bitcoin price constant.
- Hosting rates: oneminers.com/pages/hosting-centers — re-verify before acting.
This article is for information and education only. It is not financial advice. Mining results change with the Bitcoin price, network difficulty, your electricity rate and your hardware. Numbers shown are examples from public data on the date of writing, not a promise of any result. Always do your own research.
