To make an estimate or conjecture

अटकल लगाना

English Usage: I just can't guess the answer to this question.

Hindi Usage: मैं इस सवाल का जवाब अटकल से नहीं लगा सकता।

An estimation or supposition made without complete information

अनुमान

English Usage: My guess is that it will rain tomorrow.

Hindi Usage: मेरा अनुमान है कि कल बारिश होगी।