The company hit its initial goal just two and a half hours after launching the campaign on Crowdcube on Friday.
At the time of writing Grind has raised just over £1.5m from 980 investors, which the nine-strong group is planning to use to open ten new restaurants in the next five years.
Grind announced on Friday it has also signed a deal with food travel specialist SSP to launch outlets at two London travel hubs in the next 12 months. A pipeline of additional locations in airports and railway stations is under discussion.
“We've been utterly blown away by your support and kind messages,” Grind wrote on its crowdfunding page.
“But we won't be closing investment just yet - allowing those of you we've spoken to, and those we haven't, to keep investing. Now we are overfunding, we will use this to accelerate our growth plans and open more Grind's across London - faster.
“With that said, it’s unlikely the window to invest will remain open for the full 30 days as planned.”
Grind launched in Shoreditch in 2011 and raised £1.3m in a crowdfunding campaign in 2015 to fund its expansion and launch its own mobile ordering app.
Five of its sites act as restaurants with all-day menus including flat iron steak, burgers and trout, alongside coffee and cocktails.