Best way to travel between Porto, Portugal and Frankfurt

A: Porto, Portugal

B: Frankfurt

Travel Modes: Price; Distance; Duration; CO2

flight: $134.0; 1695.79 km; 5h 27mins; 183.15 kgs

train: $174.0; 2444.19 km; 34h 56mins; 129.54 kgs

bus: $174.0; 2438.82 km; 35h 51mins; 73.16 kgs

drive: $430.0; 2264.85 km; 21h 5mins; 289.9 kgs

Tranport	Distance	Time(hrs)	Cost(local)	Cost(usd)
Flight	1695.79 km	5h 27mins	99 EUR	134.0
Train	2444.19 km	34h 56mins	128 EUR	174.0
Bus	2438.82 km	35h 51mins	128 EUR	174.0
Drive	2264.85 km	21h 5mins	317 EUR	430.0

Take Train from Trindade to Aeroporto: Time: 28mins Cost: 1 EUR; $ 1.8 - 2.2 USD CO2 Emission: 0.69 kgs
Take Flight from OPO to FRA: Time: 2h 37mins Cost: 96 EUR; $ 117.0 - 143.0 USD CO2 Emission: 180.41 kgs
Take Train from Frankfurt(M) Flughafen Regionalbf to Frankfurt(M)Hauptwache: Time: 15mins Cost: 1 EUR; $ 1.8 - 2.2 USD CO2 Emission: 0.7 kgs

Source: Rome2rio

Mode of travel comparision chart

The best and cheapest way to get from Porto, Portugal and Frankfurt is to travel by air, which will cost about 99 EUR or 120.60 USD.