The best sauna stones
Stones are the thermal battery that turns a hot heater into steam. Buy the type and size your heater's manual specifies, rinse them, stack them loosely — and replace the ones that crumble.
Our sauna stones guide covers stone types, how to stack them and when to replace them. This page is the buying half: which stones to order when yours need topping up or replacing.
Quick picks
| # | Product | Best for | Key spec | Price |
|---|---|---|---|---|
| 1 | Northwood Sauna Diabase Sauna StonesDiabase is the traditional sauna stone, and this is a large enough box to fill a typical 6 kW heater with some to spare for sorting. | The overall stones pick | Authentic diabase, hand-picked, 44.7 lb box | |
| 2 | SAUNOM A+ Grade Vulcanite Sauna Rocks, 33 lbStates its stone size range — 2 to 3.5 inches — which is the specification that decides how well air moves through a heater's stone load. | Rounded stones for airflow | Rounded vulcanite, 2–3.5 in, for electric and wood heaters | |
| 3 | WILLOWYBE A+ Grade Sauna Stones, 35 lbGraded so the stones are similar in size, weight and color — consistency that makes stacking a heater easier. | Consistent sizing | Volcanic stones graded for similar size, about 35 lb | |
| 4 | NOUNGAT Rough-Cut Diabase Sauna Stones, 22 lbRough-cut diabase in a smaller box — the right size for replacing the stones that crumble out of a heater each year. | Topping up a heater | Rough-cut diabase, 22 lb | |
| 5 | TAYOI Natural Rough-Cut Diabase Sauna Stones, 19 lbA small box of rough-cut diabase — enough for a compact heater or an annual top-up. | Small heaters | Rough-cut diabase, 19 lb |
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What to look for
| Choice | What it means | What to do |
|---|---|---|
| Rock type | Diabase is the traditional choice; some boxes say only "volcanic" | Prefer a named type; follow your manual |
| Cut | Rough-cut has more surface for steam; rounded lets air move | Follow your manual; many heaters want rough-cut |
| Size | Stated sizes like 2–3.5 in let you match your heater | Match the manual's size range |
| Quantity | Boxes on this page run from 19 to about 45 lb | Check how much your heater holds |
Stone type, size and quantity for your heater are in its manual. The quantities above are the boxes' shipping weights, not a recommendation for any particular heater.
Before the first session
- Rinse the stones to remove dust, which otherwise smells when it first heats.
- Sort them, setting aside any cracked or crumbling pieces.
- Stack loosely, larger stones low and smaller higher, so air can move through the heater. A tightly packed stone load heats poorly and stresses the elements.
- Never use stones from a garden or river bed. Unknown rock can crack or spall when water hits it.
How we picked
- 1A named rock type — diabase ranked above boxes described only as "volcanic".
- 2A stated size range where one is published.
- 3Quantities that match real needs — full loads and top-ups.
- 4No health claims. We excluded a listing claiming its stones supply mineral trace elements to your body; stones make steam, not supplements.
- 5Suitability for your heater type, electric or wood.
The picks in full
Northwood Sauna Diabase Sauna Stones
Northwood Sauna
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
Diabase is the traditional sauna stone, and this is a large enough box to fill a typical 6 kW heater with some to spare for sorting.
| Stone | Diabase (subvolcanic) |
|---|---|
| Origin | Germany, per the listing |
| Shipping weight | 44.7 lb |
| Cut | Natural, hand-picked |
What works
- The traditional stone type
- Generous quantity
- Described as crack-resistant
What doesn't
- Stone size range not stated in the feature text
- Needs rinsing before first use
- Check your heater manual for the quantity it takes
Skip it ifyour heater's manual specifies a different stone type or size. Follow the manual.
SAUNOM A+ Grade Vulcanite Sauna Rocks, 33 lb
SAUNOM
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
States its stone size range — 2 to 3.5 inches — which is the specification that decides how well air moves through a heater's stone load.
| Stone | Vulcanite, A+ grade |
|---|---|
| Size | 2–3.5 in, naturally rounded |
| Weight | About 33–35 lb |
| Heaters | Electric and wood-burning |
| Thermal shock | Described as resistant |
What works
- A published size range
- Rounded stones let air circulate
- Suits wood and electric heaters
What doesn't
- Rounded stones have less surface for steam than rough-cut
- Grade labels are the seller's own
- Rinse before use
Skip it ifyour heater manual calls for rough-cut stones. Follow the manual.
WILLOWYBE A+ Grade Sauna Stones, 35 lb
WILLOWYBE
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
Graded so the stones are similar in size, weight and color — consistency that makes stacking a heater easier.
| Stone | Volcanic |
|---|---|
| Grade | A+, similar size and weight |
| Weight | About 35 lb |
What works
- Consistent sizing
- A full-heater quantity
- From a maker of wood-fired sauna gear
What doesn't
- Stone type named only as volcanic
- Size range not stated
- Rinse before use
Skip it ifyou want a specific traditional stone like diabase. This is described only as volcanic.
NOUNGAT Rough-Cut Diabase Sauna Stones, 22 lb
NOUNGAT
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
Rough-cut diabase in a smaller box — the right size for replacing the stones that crumble out of a heater each year.
| Stone | Diabase |
|---|---|
| Cut | Rough-cut |
| Weight | 22 lb |
| Surface | Porous, for heat absorption and steam |
What works
- Rough-cut for more steam surface
- A top-up quantity
- Traditional stone type
What doesn't
- Not enough to fill a large heater
- Size range not stated
- Rinse before use
Skip it ifyou are filling a heater from empty. Buy a larger quantity.
TAYOI Natural Rough-Cut Diabase Sauna Stones, 19 lb
TAYOI
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
A small box of rough-cut diabase — enough for a compact heater or an annual top-up.
| Stone | Diabase |
|---|---|
| Cut | Rough-cut |
| Weight | 19 lb |
What works
- Traditional stone
- Rough-cut surface
- Small quantity for small heaters
What doesn't
- Too few for a 6 kW heater from empty
- Size range not stated
- Rinse before use
Skip it ifyour heater takes a large stone load. Check the manual's quantity.
Pair new stones with a good bucket and ladle — throwing with the ladle, not the bucket, keeps the stones from being shocked. If you are choosing a heater at the same time, best sauna heaters sizes them to rooms.
The one we would skip
The smallest box — for filling a heater from empty.
Nineteen pounds of rough-cut diabase is exactly right for a compact heater or an annual top-up, when a few stones have crumbled and need replacing. It is not enough to fill a typical 6 kW heater from empty. Check your manual's quantity; for a full load, buy a larger box.
Questions people actually ask
What are the best stones for a sauna?
How many sauna stones do I need?
Should sauna stones be rough or round?
Can I use any rocks in a sauna?
Sources
- Amazon.com — sauna stone listings, rock types and weights as published by the sellers — checked Sep 11, 2026
- Harvia — heater specifications, including stone requirements — checked Sep 11, 2026
Read next
Every pick on this page comes from published specifications, not from hardware we own. Read how we pick — including what spec-led ranking cannot tell you.