The profit each completed buy-sell round earns after fees, and what the bot is worth if price falls to the lower bound or rises to the upper bound — the two cases a grid bot does not profit from.
Range 50,000–70,000, 20 arithmetic grids, 10,000 USDT, 0.1% fee, started at 60,000: profit per grid 1.25%–1.80%. Falling straight to 50,000 leaves the bot at 8,757.86 USDT (buy-and-hold 8,325.00); rising to 70,000 leaves it at 10,447.42 (buy-and-hold 11,655.00).
A grid bot places buy orders on a ladder of prices below the market and sell orders above it, earning a small spread each time price drops one step and comes back. This calculator shows how much each completed round earns after fees and, just as important, what the bot is worth if price leaves the range in a straight line instead of moving back and forth.
The lower and upper bounds set the range, and the start price must sit inside it. More grids mean smaller steps: more rounds complete, but each earns less, and once a step is close to twice the fee, profit per round approaches zero. Arithmetic spacing uses equal price steps, so the percentage gained per grid shrinks toward the top of the range. Geometric spacing uses equal ratios, so every grid earns the same percentage. The investment is split equally, investment ÷ grids per grid, and the fee is charged on both the buy and the sell.
Range 2,000–3,000, 10 geometric grids, 1,000 USDT, 0.1% fee, start at 2,400. The ratio is (3,000 ÷ 2,000)^(1 ÷ 10) ≈ 1.041380, so the levels run 2,000, 2,082.76, 2,168.94 and so on up to 2,880.79 and 3,000. Profit per grid = 1.041380 × (1 − 0.001)² − 1 ≈ 3.93%, the same for every grid, or about 3.93 USDT on each 100 USDT grid. If price falls straight to 2,000, the bot is worth about 877.60 USDT, against 832.50 for spending the 1,000 USDT at 2,400 and holding. If price rises straight to 3,000, the bot is worth about 1,076.11, against 1,248.75 for holding.
Those two pairs are the core trade-off. Below the range the bot ends up holding coins it bought on the way down, so it loses less than holding but still loses. Above the range it has sold everything and misses the rest of the rise. The bot only beats holding when price swings inside the range often enough for rounds to add up: here, rounds of about 3.93 USDT would have to complete dozens of times to close the 172.64 USDT gap to holding at 3,000.
The start state is simplified: grids wholly above the start price are treated as bought at the start price and the rest are held in cash. Real bots may buy their first coins with slippage, pay different maker and taker fees, and round order sizes. Above all, the calculator cannot tell you how many rounds will complete; that depends on how much price moves inside the range, which no formula knows in advance.
Reference only, not investment advice. Exchange rules (maintenance margin tiers, fee tiers, funding intervals) change; check your exchange before trading.