not far off
Partially or nearly correct; close to the truth. A: "What did that TV cost you? $3,500?" B: "Not far off—$3,750." A: "I've always suspected that he was stealing money from the company." B: "You're not far off. He's been using its offshore accounts to hide his earnings from the IRS."
not far ˈoff/ˈout/ˈwrong
(informal) almost correct: She said she thought it would be sold for $200, and she wasn’t far wrong: someone paid $235 for it.The original sales’ estimate was not far off.