Stockholm earns its expensive reputation. A round of cocktails on Stureplan will run you four hundred kronor before you've even ordered food. The good news is that the best dates here have almost nothing to do with that version of the city. Here's what to do when you don't want to spend money but you do want to have a real evening.
A korv and a walk: under 100 kronor
The Stockholm hot dog is a serious institution and the right answer to a casual first meeting. Günter's on Karlbergsvägen in Vasastan is the consensus best, around seventy kronor for a proper one with mustard and roe. Get one each, walk down to Vasaparken, sit on a bench. The whole thing takes an hour and costs less than a beer.
The upgraded version is at Korvkiosken on Bondegatan in Söder, which does small-batch sausages and craft mustards. Slightly fancier, still under a hundred per person.
Free swimming, all year: 0 kronor
Långholmen beach on the small island west of Söder is free and excellent in summer. The water is clean enough to swim in (the harbor swim tests have improved a lot in the last decade), there's a small cliff to jump off, and the whole island circuit walks in forty minutes. Bring a thermos and a blanket and that's the entire date.
In winter the same island has a wood-fired sauna at Liljeholmsbadet, the floating bathhouse from 1929, for around 130 kronor entry. A sauna and a swim in November is a more interesting date than dinner.
Museum-hopping for free: 0 kronor
Most of Stockholm's state museums are free admission. Moderna Museet on Skeppsholmen, Nationalmuseum on Blasieholmen, Historiska Museet on Narvavägen, Naturhistoriska in Frescati: all free for the permanent collections. A two-museum afternoon with a coffee in between will cost you the price of the coffee.
The pairing I'd suggest: Nationalmuseum for an hour (the Nordic 19th century rooms), walk across to Skeppsholmen, Moderna Museet for another hour, coffee at the Moderna cafe overlooking the water. Total spend, fifty kronor each.
A picnic from Hötorgshallen: around 200 kronor for two
The basement market under Hötorget is the cheapest serious food in central Stockholm. Buy a baguette from the bakery, cheese and salami from one of the deli counters, olives, a bottle of wine from Systembolaget two blocks away on Regeringsgatan. Total around 200 kronor for two. Walk to Kungsträdgården or up to Observatorielunden in Vasastan and eat on the grass.
Observatorielunden, the small hill behind the old observatory at Odenplan, has the best free view in central Stockholm and approximately no tourists.
A movie at Bio Rio: around 280 kronor for two
Bio Rio on Hornstull is a beautiful old single-screen cinema, around 140 kronor a ticket, with a bar in the lobby that opens before and after the film. A drink, a film, a walk along Hornstulls Strand afterward. The whole evening lands around four hundred kronor for two if you have one drink each.
The Sunday matinees are cheaper and less crowded, and the cafe across the street, String at Hornstull, is a good before-or-after stop.
Fika at the right place: under 150 kronor for two
Fika is the Swedish word for coffee and a pastry, and as a date format it is genuinely underrated. Vete-Katten on Kungsgatan does it properly, around seventy kronor for a coffee and a bun, and the warren of small rooms in the back of the cafe is more romantic than most restaurants. Cafe Pascal on Norrtullsgatan, around the same price, is the Vasastan equivalent.
The cardamom bun is the right order. If they're out of cardamom, the cinnamon bun is the right order.
A free concert and a beer: around 150 kronor
In summer, Kungsträdgården hosts free outdoor concerts most weekends from June through August. The lineup ranges from local indie to surprisingly big international acts. Show up an hour before, get a beer from one of the kiosks, sit on the grass. In winter, Stockholm Konserthuset on Hötorget does occasional free lunchtime concerts, which is a strange and underrated weekday date.
A practical note
The one thing worth spending money on, if you're going to spend it anywhere, is the SL transit pass. A 24-hour ticket is around 175 kronor and lets you use the metro, buses, and the commuter ferries between Slussen and Djurgården. Taking the ferry across to Djurgården at sunset is one of the better cheap moves in the city, and it counts as public transit, so it's free with the pass.