The bare, bare minimum when traveling to these places

[Jug Band Baby]

If your airfare and accommodations were covered, what is the absolute bare minimum you'd need per day to get by in the following places?  Need, not want.  Going into Buckingham Palace or into the Louvre or into whatever attractions there are in san Francisco or Germany, might be nice, but aren't needs.  This is the barest of necessities to get by, and everything else is gravy.  Just the minimum.

1) London

2) Rome

3) Stockholm

4) Paris

5) San Francisco

6) Aukland

7) Sydney

[PreciousPantsofDoom]

I'm not quite clear what information you are asking for? 

I'm assuming you are looking for average daily costs for a tourist visiting those cities, but costs vary depending on what exactly you mean by "bare minimum." (For some that means staying in a hotel without room service, for others it means sleeping in a dorm at a Hostel.)  It also varies by what type of accommodation you have chosen.  (For example; if you are staying somewhere with cooking facilities your meal costs will often be less than if you plan to eat at restaurants.)  You also have not said if you want to drive, take transit, or just walk during your vacation.

You'll get more useful answers if you define what you are asking for in a more specific way.

[FakePigtails]

Lonely Planet has the estimates you're looking for. If they're not on their website, a quick stop at your local library or bookstore should get you the info from the books.

Frommers guides are also all online but I don't recall if they do a cost estimate like LP does.

If you're on a budget, those are all expensive places and you may want to look at places in central and eastern Europe, or elsewhere, where you can get more for your money.

[Karma]

Lots of free things to do in Sydney - the beaches, coastal walks, walking across the harbour bridge.  But Sydney is an expensive city in terms of eating out and accomodation (unless as @PreciousPantsofDoom says you’re staying in a dorm in a hostel).  To buy a 600ml bottle of water in the city could easily cost you at least $3.  

When we were all young, a friend of mine backpacked in Europe.  She came home with photos of her outside Buckingham Palace, the Eiffel Tower, Windsor Castle, the Louvre etc.  She didn’t go inside any landmarks which cost money.  I think after a while she regretted that she hadn’t delayed her trip by eg a year and saved more money so that she could actually enjoy herself more.

[singsingsing]

1) London. $0 per day. I would set up residence in the Tower of London, stealthily hiding from the guards using the elite training I received as a History major, and steal food from tourists. I would earn money by following people around giving them random unsolicited facts about Henry VII's family until they paid me to go away. Once I had enough money saved I would take out a full page ad in the paper showing my family tree, whereupon the royal family would discover that Meghan Markle and I are 10th cousins once removed and immediately adopt me as their Canadian mascot, and I'd be rich.

(None of the cities you listed are in Germany, btw.)

[Jug Band Baby]

Doom, the bare minimum just to be there, presuming hotel and flights are taken care of.  The minimum upon which all else would be built.  I don't know if grocery stores are less expensive if you don't have access to a kitchen, or delis, or fast food places.  Going into museums and palaces and towers is on top of the bare minimum.

Karma, if a person takes a water bottle, are there places to fill it up?

Sing, I might have to steal your idea there, except I know too much about Henry VIII and not so much about Henry VII.

[cascarones]

I'd start with narrowing in your interests in what you want to see and research free art days if you are interested in entering museums. It really depends as well on your accommodations: Does where you're staying provide complimentary breakfast/ siesta/ happy hour? Do they provide free walking tours like most hostels? Are you bringing your own snacks? Are you staying near landmarks, the cost of food will be higher, but might be worth it to not travel to cheaper eateries. Do you intend on walking/ public transport/taxis? What is the duration of the trip, is it so short it's worth it to a hop on hop off bus to save transportation costs?

To make the most out of your trip from both an enjoyment and budget perspective, you'll have to do the more in depth research yourself. Lonely Planet, Hostel World, Trip Advisor, etc. 

[elliha]

I can't give you any sums but for London I would say that you will get more for your money if you research the hostel you stay in and look for one fairly close to a regular store and pick a hostel with a proper kitchen and then buy food to eat for lunch and dinner (some hostels have breakfast included, not a great one but good enough if you are trying to save your money). That way you can use some of that food money to try different things or go to the pub. If you want to get drunk cheaply store bought is better of course but visiting one pub at least should be mandatory even if you don't drink. London does have tons of free fun and most big museums are free at least for all the standard stuff in there. I stayed at this place twice a couple of years ago: https://www.hostelworld.com/hosteldetails.php/Astor-Hyde-Park/London/25678#propname. I was pretty pleased with this hostel and it has the store and kitchen I talked about.

I think for all these places research online before you go looking for free fun stuff will help a lot with costs. 

[Karma]

I cannot think of a single place in the city which has water refill stations - but there’s always public toilet sinks if you’re not fussy, and our tap water is perfectly safe to drink.  The Bondi Coast walk though does have bottle filling taps.  Our Art Gallery is free aside from special exhibitions.  Museums are maybe $18 (it’s been a while).  Taronga Zoo is $41 online.  Public transport all around sydney, including harbour ferries, and trains to the Blue Mountains (you’d want to go to see the Three Sisters) are max $15/day on an opal card.  You could get a basic lunch in the city for say $12.

[samurai_sarah]

London/UK:

 

The place is prohibitively expensive.

Unless you find a place, with a kitchen, food is expensive. A lot of supermarkets (e.g.: Tesco, Sainsbury's, Waitrose, Marks and Spencer's) and Boots (a pharmacy) offer "meal deals" i.e.: a sandwich, packet of crisps and a drink. The price ranges from £3.50 to £5. Eating out can be rather expensive, but it doesn't have to be. TripAdvisor will know more and specifics. For Indian food, Brick Lane in Whitechapel is famous. It's also where the 24 hour Bagel Shop is located, an East End institution, dating back to the times when the East End was mainly home to displaced Jews from Eastern Europe.

Additional bonus: It's where Jack the Ripper committed his crimes. The "Ten Bells" pub is around the corner. It's associated with some of his victims, and retains its Victorian interior. Another free-of-charge activity is to visit Spitalfields' Market around the corner. It's a huge market hall with stalls that sell everything imaginable.

Another free activity I always rather enjoyed: Trundling around the Inns of Court and peeking into the church of the knights Templar. It's a sudden oasis of calm, off bustling, busy Fleet Street. Around there, you also encounter "Prince Henry's Room", one of the few houses that survived the Great Fire of London 1666.  Alas, not viewable from the inside. At the end of Fleet Street, where it forks into Aldwych and the Strand, you'll find St-Clement-Danes, opposite the Royal Courts of Justice. Gory legend has it that the church portals were once covered with the flayed skins of Viking invaders. (Spoiler: Not true.)

From there it isn't far to Covent Garden. The Market Hall on the piazza is interesting to wander around in for window-shopping. If you walk further towards Leicester Square and Shaftesbury Avenue, you are in the heartland of London's theatre and musical scene. The ticket offices are a good place to snap up cheap last minute tickets for shows that aren't sold out yet, or to find someone selling tickets that they shouldn't. "Time Out" is "the" magazine that comprehensively lists everything going on in London, in terms of entertainment.

The National Gallery and the National Portrait Gallery (free entry for both) aren't far from Leicester Square. They're on Trafalgar Square, which is also where the church St Martin-in-the-Fields is located. Only important if you like classical music on a budget in a historic building. Different choirs and orchestras put on events by candlelight. They're basically doing a dress-rehearsal in candlelight, while you get to hear them at a discounted price...in candlelight. Some are first-come-first-serve, other concerts are for free.

From Trafalgar Square you only have to walk down the Pall Mall to reach Buckingham Palace (not open to the public, save on special occasions), but watching the guards change is a spectacle that's free of charge. Get there early to get a good spot!

Transport in London is expensive. The cheapest way around is walking. Obviously not an option if you find cheap accommodation in the Greater London area and want to see central London. Forget Day Tickets, buy an "Oyster Card". An Oyster Card is like a debit card for Transport for London (TFL). You can use it for the tube, busses and TFL-run boats on the Thames. Far cheaper to go on a boat tour from central London to Greenwich on a regular TFL ferry, than going on a tourist boat tour.

A load of museums are free of charge and are well worth a visit. The Tower of London is expensive (£21.50 for an adult without concessions), but some hop-on-hop-off tours include entrance to the Tower (I forget which).

Everyday cost as a bare-necessities tourist: I'd say around £50. Less, if you just walk around, avail yourself of all the free stuff, and bring your own water and coffee. If you have accommodation in central London, and are okay with walking for hours, the cost goes down.

London is do-able on a shoe-string. But @singsingsing's plan is cheaper.

[elliha]

I am Swedish but I must admit that I have never been to Stockholm as a real tourist, only for practical matters. It is quite expensive, similar to London. On a budget I would not eat out in Stockholm and if I had to only at lunch as most places have some kind of offer for lunch. I would follow the same policy of buying food in stores when possible. In summer there are different boats you can take between the islands of Stockholm and boats into the archipelago, that would be something I would consider spending some money on too myself. 

However, to be honest, if you want to see Sweden as a country I would not go to Stockholm, try Gothenburg or Malmö if you want a bigger town and then it would be possible to do a double with Denmark too. If you want to go north try Luleå, Jokkmokk or Kiruna. If you go in summer you go to the land of the midnight sun if you try the two latter ones and the first will give you nights that are light all day but not technical midnight sun. If you go in the middle of winter you get darkness instead. I am from the north and I love the long light summer days. Many non-natives to the region find the light nights hard on them as they can't sleep. 

[laPapessaGiovanna]

For me the bare minimum wherever you decide to go would be to make sure you have healthcare in case something happens. Also make sure that if you are incapacitated or unable to move you have medically assisted transportation back home.

I would also make sure to have internet connection on my mobile. Here in Italy many places offer free wifi to customers, but often it doesn't work, so better be sure to have your own.

[adidas]

I live a couple of hours from Sydney and when I go there for work I am allocated a daily budget. Here are the amounts I am compensated (so I try to stick to budget).

$60 per day for two taxi fares (usually no more than a few km at a time eg Surry Hills to Leichhardt)

$20 for lunch

$40 for dinner

I am usually supplied with water bottles but cost $3-ish each

Parking can be expensive - if I hire a car (it’s been a while but from memory maybe $70 per day) it can cost over $50 per day to park in the city

most places have free wifi

If you want to move past the needs and venture into wants, Sydney can be expensive. There are lots of free activities though.

https://www.google.com.au/amp/s/www.lonelyplanet.com/amp/australia/sydney/travel-tips-and-articles/20-free-things-to-do-in-sydney/40625c8c-8a11-5710-a052-1479d277bb4d