Cheapest way from Paddington Station to Windsor castle (4 children and 2 adults)

What's the date?

Correction: Wednesday, April 4.

Enter the date and stations into the National Rail planner.

http://ojp.nationalrail.co.uk/service/timesandfares/PAD/WNC/tomorrow/0845/dep#outwardJump

It says the lowest fare for 2adults and 4chiodren is an Off-Peak day return”. With the group discount applied, the fare is £40.80 for the return ticket for all. You must observe the off-peak travel hours.

Thank you very much. Just to clarify, is this a round trip price or one way?

"return" is British for "roundtrip". Important to know this. "Single" is "one way".

Oh THANK YOU!!

Yes, that is round-trip. Just make sure that you depart from Paddington after 9 am. You will have to figure out what the off-peak travel time is for the return trip back to Paddington. It there may not be a restriction. I entered it as a same-day round trip in the journey planner and it showed all trains throughout the afternoon and evening as available for that same price.

Fantastic! You have been immensely helpful. Thank you.

You will change trains in Slough (rhymes with "cow"). You will go from your big train to a little shuttle train for the short run around the corner to Windsor and Eton Central station. Off the little train into the shopping centre which has taken over most of the station, and out of the station the Castle is just across the street.

When you arrive in Windsor as you exit the train, turn left and walk up to the road. As Nigel said, the castle will be right across the road. When you get to the road turn to your right and walk to the corner, cross the road (there will be a statue of Queen Victoria) to Castle Hill walk straight up to the entrance. If you have time after touring the castle walk back down to the road by the statue, turn to your left and follow the road down to Windsor Great Park, you have a fantastic view of the royal resident part of the castle from the park. The road you see is called the Long Walk, it’s the private road for the royal family to enter and exit the castle.

Just daydreaming and looking at Windsor in Google Maps, I spotted a large jet landing, headed for Heathrow, just south of the Victoria Barracks. I suppose not that uncommon. Zooming in says American Airlines.

https://www.google.com/maps/@51.4777519,-0.6108568,905m/data=!3m1!1e3

It is absolutely true that both Windsor Castle and Kew Gardens are most definitely under the flight path for Heathrow. You can look up and see (and hear) tourists landing every few minutes.