Chalmers began sketching at a young age, and by 1851 he was painting oil portraits of locals in his native Montrose. This eventually earned him enough money to move to Edinburgh, where at the age of twenty he became a student of the Trustees' Academy under Robert Scott Lauder. Despite this education, he never became an accomplished draughtsman, but his loose handling of paint often conceals this. He had a particular talent for capturing the effects of light and colour as well as a strong appreciation of the picturesque. Chalmers settled in Edinburgh where he led a quiet and uneventful life painting portraits, genre, and landscape. This was varied by occasional painting trips to Ireland, Skye, Glenesk, and even Europe. He was elected an Associate of the Royal Scottish Academy in 1867, and a full member in 1871.