Best way to travel between Istanbul, Turkey and Sofia

A: Istanbul, Turkey

B: Sofia

Travel Modes: Price; Distance; Duration; CO2

train: $18.0; 592.25 km; 14h 28mins; 31.39 kgs

bus: $20.0; 566.61 km; 10h 19mins; 17.0 kgs

drive: $110.0; 562.02 km; 6h 35mins; 71.94 kgs

flight: $124.0; 524.28 km; 4h 4mins; 56.62 kgs

Tranport	Distance	Time(hrs)	Cost(local)	Cost(usd)
Train	592.25 km	14h 28mins	26 BGN	18.0
Bus	566.61 km	10h 19mins	29 BGN	20.0
Drive	562.02 km	6h 35mins	159 BGN	110.0
Flight	524.28 km	4h 4mins	179 BGN	124.0

Take Train from Istanbul Sirkeci Terminal to Kapıkule: Time: 5h 6mins Cost: 12 BGN; $ 7.2 - 8.8 USD CO2 Emission: 13.83 kgs
Take Train from Kapikule to Plovdiv: Time: 4h 38mins Cost: 9 BGN; $ 5.4 - 6.6 USD CO2 Emission: 9.24 kgs
Take Train from Plovdiv to Sofia: Time: 3h 4mins Cost: 6 BGN; $ 3.6 - 4.4 USD CO2 Emission: 8.36 kgs

Source: Rome2rio

Mode of travel comparision chart

The best and cheapest way to get from Istanbul, Turkey and Sofia is to travel by train, which will cost about 26 BGN or 16.20 USD.