How much does mining earn? Calculating your profitability
How much does a mining machine earn, and how long does it take to pay for itself? It is the question we are asked most often before a purchase. In this video (in French), we show you step by step the method we use to calculate the profitability of a graphics card rig, with worked examples.
Video published on 21 October 2021: the figures below date from that time. See "What about today?" at the end of the article.
1. Estimate daily earnings with WhatToMine
The starting point is the WhatToMine website. You select the card model and the quantity (6 × RTX 3070 in our example), enter your electricity price and run the calculation. The site ranks algorithms and cryptocurrencies from most to least profitable, with two figures: gross earnings over 24 hours, and net earnings once electricity is deducted.
Two things to watch:
- The price per kWh: WhatToMine defaults to $0.10. In France it was closer to $0.16 at the time.
- The default card values: they are approximate. A well-tuned RTX 3070 mines slightly faster and draws less power than the site shows, and on some algorithms the real consumption is clearly lower than the estimate. These differences move the result by 5 to 10%.
2. Calculate the return on investment
Once you know the net daily earnings, the calculation is simple:
payback time (in days) = purchase price ÷ net earnings per day
This only covers the cards. You have to add the rest of the rig (motherboard, power supplies, frame, risers), which cost €700 to €900 at the time depending on the number of cards.
3. Compare cards by price per MH/s
The most powerful card is not necessarily the most profitable: it all depends on its price. To compare, divide the price of the card by its hashrate. Our rule: no more than €15 to €17 per MH/s. Our examples, at October 2021 prices:
- GTX 1660 Super: about 32 MH/s, at €450 maximum, i.e. €14 per MH/s;
- RTX 3060 LHR: about 33 MH/s with a partial unlock, at €550 maximum, i.e. €16.60 per MH/s;
- RTX 3060 Ti LHR: about 42 MH/s with a partial unlock, around €700, i.e. €16.50 per MH/s;
- RTX 3060 Ti non-LHR: about 61 MH/s, rarely below €950, i.e. €15.50 per MH/s;
- RTX 3080 non-LHR: about 100 MH/s, worth it up to €1,500, i.e. €15 per MH/s;
- RTX 3090: about 120 MH/s, at €2,000–2,100 maximum, i.e. under €17 per MH/s.
An LHR card, limited by NVIDIA, is therefore not necessarily less profitable than an unrestricted one: it costs less, and mining software such as NBMiner, T-Rex or GMiner could recover part of its hashrate. Be careful, however, with cards using GDDR6X memory (RTX 3080, 3090…), which run very hot: an overheating card lowers its hashrate or even crashes the rig. On our RTX 3090 Founders Edition, we had to replace the thermal pads.
4. The result: 8 to 9 months to pay back the cards
With the net earnings shown on WhatToMine on 21 October 2021 (about €1.92 per day for a GTX 1660 Super, €7.40 for an RTX 3090), the cards in the example paid for themselves in 8 to 9 months, and in under 8 months for a GTX 1660 Super bought at €450. Ethereum was then worth about €3,500 to €3,700.
5. The factors that drive profitability
- The price of the machine, its hashrate and its power consumption;
- The price of electricity;
- Mining difficulty: the more computing power on the network, the more miners the reward is shared between. It tends to rise: on Ethereum it had more than doubled between the start and the end of 2021;
- The price of the coin being mined;
- Resale value: a latest-generation card (RTX 3000, RX 6000) resells more easily and for more than an older model (GTX 1660, RTX 2000, RX 400/500).
Hence two main strategies: buy recent hardware, more expensive but longer-lasting and easier to resell, or look for cheaper second-hand hardware. Many miners combine the two.
What about today?
Since Ethereum moved to proof of stake in September 2022, Ethereum can no longer be mined with graphics cards, and the figures above are out of date. The method, however, still applies to ASIC miners: compare the price per TH/s (or GH/s), the efficiency in J/TH, the price of electricity and the network difficulty.
To estimate the profitability of a Bitcoin miner, use our Bitcoin mining profitability calculator and browse our ASIC miners. No space or no cheap electricity at home? Have a look at our miner hosting, or contact us for advice before you buy.