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What most people overlook: the 40.5 % reduction covers only the first CHF 500,000 of gain. The section on the holding period shows what that means for a CHF 700,000 gain.
| Gain | Basic tax (Article 140) | Tax 2026 (× 325 % total multiplier) |
|---|---|---|
| CHF 100,000 | CHF 7,520 | CHF 24,440 |
| CHF 150,000 | CHF 12,520 | CHF 40,690 |
| CHF 300,000 | CHF 27,780 | CHF 90,285 |
| CHF 500,000 | CHF 49,000 | CHF 159,250 |
| above CHF 600,000 | 10 % of the whole gain | 32.5 % of the whole gain |
Calculation · St. Gallen Tax Act
How do I calculate property gains tax in the Canton of St. Gallen?
You calculate St. Gallen property gains tax in four steps: gain, basic tax, total tax multiplier (Gesamtsteuerfuss), then years owned. The gain is sale price minus investment costs (Anlagekosten). These are your purchase price plus improvements that added value (Article 134). On the gain, the canton charges a basic tax in bands up to 11 % (Article 140).
What sets St. Gallen apart: this basic tax is multiplied by the total multiplier, 325 % in 2026. That is a 105 % cantonal rate (Kantonssteuerfuss), set yearly, plus 220 % fixed by law. A CHF 12,520 basic tax on a CHF 150,000 gain becomes CHF 40,690. Only then do years owned count (Articles 6–7 Tax Act, StB 6 No. 1, as of 1 January 2026).
What this means for you: tax, selling costs and mortgage come off the sale price. The rest is money for your next home. You can only estimate the biggest figure: your sale price.
The formula is in the law; your sale price is not. We derive it in writing and show what remains after tax, costs and mortgage. So you and your family can plan the next step with a traceable figure, before anyone signs.
Deductions · Investment costs and substitute value
Which deductions lower property gains tax in St. Gallen?
Improvements that added value lower St. Gallen property gains tax, as do buying and selling costs. These include adverts and customary estate agent fees (Article 137). So does the early repayment charge (Vorfälligkeitsentschädigung) when the sale ends a fixed-rate mortgage early (StB 137 No. 1). Maintenance already deducted for income tax does not count (Article 137(2)).
If you bought over 20 years ago, a substitute value (Ersatzwert) may replace the purchase price (Article 139(3)). That is the official market value (Verkehrswert) 20 years ago, the realistic price then. Improvements then count only from the last 20 years. The reduction assumes 20 years owned: 7.5 % at most. If you lived there under 15 of them, it is 5 % (Article 141(4)).
What this means for you: the substitute value can lower the gain but shrink the reduction. After 46 years in your own home, that is 7.5 % instead of 40.5 % on the first CHF 500,000 of gain. Only calculating both shows which is cheaper.
Worked example
Worked example: how a CHF 700,000 gain becomes CHF 227,500 tax.
A CHF 700,000 gain after eight full years, calculated with the 2026 total tax multiplier. Above CHF 600,000, St. Gallen replaces the bands with a single 10 % on the whole gain, then multiplies by 325 %. After decades in your own home, the numbers look different; the next section shows how.
- Property gain: sale price minus investment costs
- CHF 700,000
- Basic tax: a single 10 % on the whole gain, because it exceeds CHF 600,000 (Article 140(3))
- CHF 70,000
- Total tax multiplier 2026: cantonal rate of 105 % plus 220 % added by law (Articles 6 and 7, StB 6 No. 1)
- 325 %
- Tax amount: CHF 70,000 times 325 %
- CHF 227,500
- 8 full years of ownership: no surcharge, which applies only under 5 years; no reduction, which starts only from the 16th full year (Article 141)
- CHF 0
- Property gains tax
- CHF 227,500
Holding period · Surcharge and reduction
How does the holding period affect property gains tax in St. Gallen?
St. Gallen property gains tax rises 1 % per year short of five and falls after 15 full years. If you lived there for at least 15 years, it falls 1.5 % a year over 15. The reduction reaches 40.5 %, but only on the first CHF 500,000 of gain. Otherwise it is 1 % a year over 15, up to 20 % (Article 141).
The official calculator shows: a CHF 700,000 gain after 55 years, owner-occupied, costs CHF 149,353, not 227,500. The reduction is CHF 78,147, not 40.5 % of the whole tax. That is 40.5 % of the CHF 159,250 tax on the first CHF 500,000 of gain, plus 20 % of the rest. The law sets the threshold, not the split.
What this means for you: on gain above CHF 500,000, only the smaller reduction applies. Living there does not change that part. Our calculator splits it the same way. After an inheritance, your parents’ purchase counts; see selling an inherited house.
To be honest
When does waiting lower St. Gallen property gains tax?
The reduction starts after more than 15 full years, counted to the day from your entry in the land register (Grundbuch). That is the official record of who owns a property. An example at the official tax calculator: a CHF 250,000 gain, owner-occupied, bought on 2 January 2010, sold on 1 January 2026. That is 15 full years and CHF 73,222 tax.
Bought one day earlier, it is 16 years and CHF 72,123: CHF 1,099 less for a single day. Waiting also pays under five years. A CHF 100,000 gain after 4 years and 11 months costs CHF 24,684; after five full years, CHF 24,440. After 42 full years with at least 15 in your own home, waiting brings no further reduction; otherwise, after 35.
Whether keeping is better does not depend on tax alone; the home check: keep, adapt or something new helps. The law does not say explicitly which date counts as the sale date; ask the Cantonal Tax Office (Kantonales Steueramt) before you sign.
What do owners ask about property gains tax in St. Gallen?
How accurate is the property gains tax calculator for St. Gallen?
To within CHF 2 at most, if your details are right and you have owned the house for 40 years or less. Tested cases at the official tax calculator show this. Our calculator applies the scale, the 2026 total tax multiplier and the St. Gallen reduction rules, and rounds like the official one. One limit: if it chooses the substitute value, it counts all the improvements you enter. The law allows only those from the last 20 years.
The result is an estimate, not a tax ruling. What counts is the tax assessment (Veranlagung), the decision of the Cantonal Tax Office. The greatest uncertainty usually lies in your estimated sale price. When calculating for your parents, keep the purchase contract and invoices at hand, so the figure you pass on rests on documents.
Are my entries saved?
No. The calculator works on your device, and you need no account. We only receive what you enter in a form, once you send it yourself.
Is there a tax allowance for property gains tax in St. Gallen?
Yes, CHF 2,200. The first CHF 2,200 of gain is taxed at 0 % (Article 140(1)(a) St. Gallen Tax Act). Above a gain of CHF 600,000 this falls away, because a basic tax of 10 % then applies to the whole gain. The canton does not collect a tax of CHF 50 or less (Article 215 Tax Act; Article 88 Tax Ordinance, Steuerverordnung).
Can I get an advance calculation of property gains tax in St. Gallen?
Yes. The website of the Cantonal Tax Office St. Gallen offers the form «Vorausberechnung der Grundstückgewinnsteuer» (advance calculation) and the official tax calculator, in German. The tax is assessed by the Cantonal Tax Office St. Gallen, property gains tax department. It is a cantonal tax (Staatssteuer), levied by the canton itself (Article 1(d) St. Gallen Tax Act).
The official calculator shows the tax. The Immosmile calculator also shows what remains after costs and mortgage. If the house is in another canton, you can calculate property gains tax for other cantons.
Does the calculator include a replacement purchase for St. Gallen property gains tax?
Yes. A replacement purchase (Ersatzbeschaffung) defers the tax when the proceeds go into a new home of your own. Choose «Yes, replacement purchase» and enter the price of the new home you will live in. Deferral covers only what the new home costs above your old investment costs, at most the whole gain (tax manual StB 132 No. 6).
This applies to a home you live in yourself, permanently and exclusively, replaced by one used the same way in Switzerland. You buy the new home within three years after the sale; a purchase up to one year before also counts (Article 66 Tax Ordinance). The tax is only deferred, not waived. What else applies to selling a house in the Canton of St. Gallen is on our canton page.
Do I have to sell with you after the valuation?
No. The valuation and first conversation are free and without obligation. That also applies if, in the end, we recommend keeping it. You receive a written valuation of your house with a full net calculation. It explains how we reach the sale price, and then you decide in your own time.
Sources
- Tax Act of the Canton of St. Gallen (Steuergesetz, sGS 811.1), Articles 1, 6–8, 130–141, 215 (German) · 1 January 2026
- St. Gallen tax manual (Steuerbuch) StB 6 No. 1: tax multiplier by year (German) · version of 1 January 2026
- St. Gallen tax manual StB 140 No. 1: calculating the tax and the rates (German) · version of 1 January 2016
- St. Gallen tax manual StB 137 No. 1: deductible expenses (German) · version of 1 January 2022
- St. Gallen tax manual StB 141 No. 2: reduction for long ownership (German) · version of 1 January 2025
- Official property gains tax calculator, Canton of St. Gallen (German) · accessed on 29 September 2026
General information, not individual advice. The law, the tax assessment and advice from professionals for your situation are what count.
