Thank you Google 🙂
Try this free one..
From the site:
WTCC II is a four function time code calculator that supports calculations, and conversions, in: NTSC, Drop-Frame, Non Drop-Frame, PAL, Film Feet and Frames, Decimal, Hex and Octal values. Additional features of WTCC include a “tape” and conversion between decimal and Roman numerals.
I just tried it (XP Pro SP2) and it works as advertised. HTH.