How the BloFin ETHUSDT perp order box actually counts your size: 1 contract = 0.01 ETH

[Trading setup] If you type 1 into the size box on BloFin's ETHUSDT perpetual and think you bought 1 ETH, you bought 0.01 ETH. BloFin's public instrument data lists the ETH-USDT swap with a contract value of 0.01 ETH, a minimum size of 0.1 contracts, a lot step of 0.1 and a price tick of 0.01. Getting that unit right is step one of setting up a first trade.

The image is BloFin's live ETHUSDT perpetual page this afternoon, with the price header, chart and order book.

Setting up the order, in the order you actually click it:

1. Margin mode. Isolated keeps the loss on this position to the margin you put in it. Cross lets the position draw on your whole futures balance. For a first trade, isolated is the easier one to reason about.
2. Leverage. BloFin allows up to 150x on ETH-USDT. Leverage does not change how much ETH you hold; it changes how much margin you post for it.
3. Size. Decide in ETH, then convert: 1 ETH = 100 contracts, 0.5 ETH = 50 contracts. The smallest order, 0.1 contracts, is 0.001 ETH.
4. Order type. Limit if you care about the price, market if you care about getting filled now. A single market order is capped at 200,000 contracts (2,000 ETH); limit orders at 600,000.
5. TP/SL. Attach them on the order so the exit exists before the trade does.

Worked example with the API numbers at about 4:16 PM ET (last 2,316.03):

• Size: 100 contracts = 1 ETH = 2,316.03 USDT notional
• At 10x: margin = 2,316.03 / 10 = 231.60 USDT
• Funding at the current +0.022% per 8h: 2,316.03 x 0.00022 = about 0.51 USDT per settlement, paid by longs
• 24h range: 2,292.79 to 2,351.58, or 58.79 points, about 2.5% of price. At 10x, a full-range move against you is roughly 25% of that margin.

The same contract-value check matters on other pairs too, since BTC, SOL, XRP and DOGE perps all carry their own contract value. Read it once per symbol before your first order.

Checklist before you press Buy/Long: margin mode set, leverage set on purpose, size converted to contracts, order type chosen, TP and SL attached.