The dasha balance at birth: learn with a slider

However far the Moon has travelled through its nakshatra at birth, that much of the nakshatra lord's dasha counts as already spent.

Balance of Ketu dasha: 3 years 5 months 30 days

Balance = (13°20′ − the Moon's travelled part) ÷ 13°20′ × {lord}'s full dasha

On average, one degree of the Moon is about one year of dasha (from 6 months to a year and a half, by planet).

Classical text · BPHS (Santhanam) 46.12–15 (Vimshottari order and years)
BPHS (Santhanam) 46.12–15 (Vimshottari order and years)