There’s a good network of 65 official HI hostels (http://www.hostellit.fi) as well as a few independents. Most charge €5–6 for breakfast and bed linen is often extra, too (€4–7), so if you’re on a tight budget it’s worth bringing your own sheets. Dorms are almost always single-sex. The free Finland: Budget Accommodation booklet, available from any tourist office, contains a comprehensive list of hostels and campsites.
Hotels are expensive. Special offers in summer mean that you’ll be able to sleep well on a budget in high season, but may have difficulty finding anything affordable out of season – the reverse of the norm. In many towns you’ll also find tourist hotels (matkustajakoti) offering fewer frills for €35–50 per person, and summer hotels (kesähotelli; June–Aug only), which offer decent accommodation in student blocks for €25–45 per person.
Official campsites (leirintäalue) are plentiful. The cost to camp is roughly €10–12 per pitch, plus €3–4 per person, depending on the site’s star rating. Most open from May or June until August or September, although some stay open longer and a few all year round. Many three-star sites also have cottages, often with TV, sauna and kitchen. To camp in Finland, you’ll need a Camping Key Scandinavia, available at every site (and online: camping.fi) for €16 and valid for a year. Camping rough is illegal without the landowner’s permission – though in practice, provided you’re out of sight of local communities, there shouldn’t be any problems.