How Long to Boil Potatoes? (Small, Medium, Large Guide)

Here is the honest answer to how long to boil potatoes: it depends on the size. Small whole potatoes take about 15 minutes in boiling salted water. Medium ones (the size of a tennis ball) need 20 to 25 minutes. Large potatoes can take 30 to 35 minutes. Cubed potatoes, regardless of variety, are done in 12 to 15 minutes. I know these times because I have botched more than my share of mashed potatoes by guessing – and after years of cooking I have landed on a system that works every single time. The single most reliable test is not a timer; it is a fork or paring knife poking through the thickest part with zero resistance.

The potato type also matters. Waxy potatoes like red bliss and fingerlings hold their shape after boiling and work best for potato salad. Starchy potatoes like russets fall apart beautifully for mashed potatoes but get waterlogged if you overcook them. Yukon Golds sit in the middle and are the most forgiving to boil. This guide covers every size, every type, and every important technique so you never have to guess again.

Why You’ll Love This Recipe

• Covers every size with exact times so you never undercook or overcook again
• Includes a full breakdown by potato variety so you pick the right type for what you’re making
• Explains the cold-water start vs. hot-water start debate with a clear recommendation
• Teaches the fork test so you can verify doneness without relying only on a timer
• Works as a reference you’ll come back to every time you cook potatoes, no matter the recipe

About This Multi-Brand Favorite

Boiling potatoes is one of the oldest cooking techniques in the world, and yet it produces wildly inconsistent results in most home kitchens. The problem is not the method – it is the lack of a repeatable system. Professional cooks don’t guess; they start with cold water (which heats the potato evenly from the inside out rather than cooking the outside faster than the inside), they salt the water aggressively (which seasons the potato flesh rather than just the surface), and they always test with a knife before draining rather than trusting a timer alone. The cold-water start method is particularly important for mashed potatoes because it prevents the outside from becoming waterlogged and falling apart before the inside is cooked. For salads and roasted potatoes, where you want the shape to hold, a cold-water start followed by attentive timing and an immediate drain is the key to firm, evenly cooked results.

Ingredients

What You’ll Need

• Potatoes (any variety – see size guide for exact timing)
• Small whole potatoes (1-2 inches): about 15 minutes
• Medium whole potatoes (2-3 inches): 20-25 minutes
• Large whole potatoes (3+ inches): 30-35 minutes
• Cubed potatoes (1-inch pieces): 12-15 minutes
• Halved small potatoes: 15-18 minutes
• Large pot (at least 4-quart) filled with cold water

Potato Variety Guide

• Russet potatoes: high starch, fluffy texture, best for mashing and baking
• Yukon Gold: medium starch, buttery flavor, great all-purpose boiling potato
• Red bliss: waxy, holds shape well, ideal for potato salad
• Fingerling: waxy, stays firm, best for salads and side dishes
• New potatoes: thin skin, tender, excellent for boiling whole

For Finishing

• Butter and salt for simple mashed potatoes
• Olive oil, vinegar, and fresh herbs for potato salad
• Sour cream and chives for loaded baked-potato style

Ingredient Substitutions

• If you only have large potatoes but need them fast, cut into 1-inch cubes to cut the boiling time down to 12-15 minutes
• Sweet potatoes can be boiled using the same size-based timing but they cook about 5 minutes faster than regular potatoes at each size
• If you do not have kosher salt, table salt works – use about two-thirds the amount since it is denser
• A pressure cooker (Instant Pot) reduces boiling time dramatically: whole medium potatoes take about 12 minutes at high pressure
• For potato salad specifically, waxy red or fingerling potatoes can replace each other at a 1-to-1 ratio with nearly identical results

Equipment You’ll Need

• Large pot (4-quart minimum) – potatoes need room to move or they cook unevenly
• Colander for draining
• Timer (but always verify with a knife test too)
• Paring knife or fork for the doneness test
• Lid optional – the pot does not need to be covered once boiling

Step-by-Step Instructions

1. Start with cold water, not boiling. Place the potatoes in the pot and cover with cold water by at least one inch. Starting in cold water is important – it allows the potato to heat gradually and evenly from the inside out. If you drop potatoes into already-boiling water, the exterior cooks faster than the interior, giving you a mushy outside and an undercooked center. This step matters most for whole potatoes; for cubed potatoes it is less critical but still a good habit.
2. Salt the water generously. Add at least one tablespoon of kosher salt per quart of water before turning on the heat. This is not optional. Potatoes boiled in unsalted water taste flat no matter how much butter you add afterward – the salt needs to penetrate the flesh while it cooks. The water should taste pleasantly salty, like a light broth. This is the single most important flavor decision in boiling potatoes.
3. Bring to a boil, then reduce to a steady simmer. Bring the water to a full rolling boil over high heat, then reduce to a strong simmer – you want bubbles breaking the surface steadily but not a violent rolling boil. A hard boil can knock the potatoes around and break up waxy varieties or cause russets to get waterlogged on the outside. Start your timer once the water reaches a steady simmer, not when you first turn on the heat.
4. Use the correct time for your potato size. Follow the size guide: small whole potatoes need 15 minutes, medium whole potatoes 20-25 minutes, large whole potatoes 30-35 minutes, and 1-inch cubes 12-15 minutes. These are starting points – the fork test in the next step is the real confirmation. Thicker-skinned varieties like russets tend toward the longer end of the range; thin-skinned varieties like new potatoes are usually done at the shorter end.
5. Test for doneness with a knife or fork. Starting a couple minutes before your timer goes off, pierce the thickest part of the largest potato with a paring knife or a fork. For mashed potatoes, you want zero resistance – the knife should slide in and out with no effort at all. For potato salad or roasting, you want the knife to meet slight resistance at the center – the potato should be cooked through but still holding its structure. If there is resistance for mashed, give it 3 more minutes and test again.
6. Drain and handle based on intended use. Drain the potatoes in a colander immediately when they reach the right doneness – do not leave them sitting in hot water or they continue cooking. For mashed potatoes, return them to the hot pot for 1-2 minutes over low heat to steam off excess moisture before mashing – this makes fluffier mash. For potato salad, rinse briefly under cold water to stop cooking and cool slightly before dressing.
7. Season and finish immediately. Potatoes absorb salt, butter, and seasoning best while still hot. If you are making mashed potatoes, start adding your butter and cream while the potatoes are steaming hot. If you are making potato salad, dress the potatoes while they are still warm – they absorb the vinaigrette and seasoning much better than when cold. Season and taste before serving; potatoes need more salt than you expect.

Pro Tips from My Kitchen

• For the most evenly cooked results, choose potatoes that are similar in size – or cut them to the same size before boiling
• If boiling whole potatoes for potato salad, start in cold water and do not cut or pierce them before cooking – the skin acts as a barrier keeping them from getting waterlogged
• For extra-fluffy mashed potatoes, drain the cooked potatoes and let them steam dry in the hot pot for 2 minutes before mashing – the drier the potato, the more butter and cream it can absorb
• Test the water saltiness before adding potatoes – it should taste visibly salty like a light broth
• Small potatoes boiled whole for salad can be halved after cooking rather than before – the flat cut surface won’t waterlog during boiling
• Add a bay leaf and a few smashed garlic cloves to the boiling water for subtle background flavor that comes through even in mashed potatoes

Recipe Variations

• Pressure cooker method: Whole medium potatoes at high pressure take about 12 minutes – great when you’re in a rush
• Steam instead of boil: Steaming takes slightly longer but produces a less waterlogged potato, especially good for russets destined for mashing
• Add a splash of white vinegar to the boiling water to help waxy potato varieties hold their shape better during potato salad prep
• Boil with the skins on for mashed potatoes, then rice through a food mill for ultra-smooth results without any manual peeling beforehand
• For German-style potato salad, drain potatoes and dress immediately in warm bacon drippings and vinegar while they’re still hot from the pot

Common Mistakes to Avoid

• Starting potatoes in already-boiling water instead of cold water – causes the outside to overcook before the inside is done
• Not salting the water – potatoes boiled in plain water taste flat no matter how well you season them afterward
• Going by the timer alone without doing the fork test – potato sizes vary and timers are a starting point, not a guarantee
• Leaving drained potatoes sitting in the colander too long before mashing or dressing – they get gummy and lose their ability to absorb butter and seasoning
• Boiling at a violent rolling boil instead of a steady simmer – damages the texture of waxy potatoes and makes russets waterlogged on the outside

What to Serve With This Dish

• Mashed potatoes alongside any braised or roasted protein – the boiling guide directly feeds your best mashed potato recipe
• Classic American potato salad for summer cookouts – requires waxy potatoes boiled just until tender
• Home fries – boil potatoes until almost done, then cube and crisp in a skillet with butter and onion
• Potato soup or chowder – cubed potatoes boiled in broth form the base of dozens of comfort soups
• Hash browns and breakfast potatoes – par-boiling potatoes before shredding or dicing gives you crispier results in the skillet

Storage Instructions

Refrigerator

Boiled potatoes keep in an airtight container for up to 4 days. Cooked potatoes tend to firm up as they cool due to starch retrogradation, so they are often best used the day they are cooked for mashing.

Freezer

Mashed potatoes freeze well for up to 3 months. Plain boiled whole or cubed potatoes tend to become grainy and watery after freezing and thawing and are not recommended for freezer storage.

How to Reheat

Reheat mashed potatoes with a splash of milk or cream in a saucepan over low heat, stirring frequently. Boiled whole or cubed potatoes reheat best in a skillet with a bit of butter rather than in the microwave, which makes them rubbery.

Make Ahead

Boil potatoes up to 2 days ahead and refrigerate. For potato salad, dress them right before serving. For mashed potatoes, reheat gently with added cream to restore the texture.

Nutrition Information

Per serving (estimated): 160 calories, 4g protein, 37g carbs, 0g fat (0g saturated), 3g fiber, 2g sugar, 15mg sodium.

Nutrition values are estimates and will vary based on exact ingredients used.

Frequently Asked Questions

Should I start potatoes in cold water or boiling water?

Cold water is almost always the better choice. Starting in cold water lets the potato heat gradually and evenly throughout. Dropping potatoes into boiling water cooks the exterior faster than the interior, which can leave you with an overcooked outside and an undercooked center – especially in larger whole potatoes.

How much salt should I add to the boiling water?

At least 1 tablespoon of kosher salt per quart of water. The water should taste noticeably salty – like a light broth. This is the primary opportunity to season the interior of the potato, and no amount of salt added afterward can fully compensate for unsalted boiling water.

How do I know when boiled potatoes are done?

Use a knife or fork test, not just a timer. Pierce the thickest part of the potato – for mashed potatoes you want zero resistance, the knife should slide in and out freely. For potato salad or other uses where shape matters, look for slight resistance at the center indicating it’s cooked through but still firm.

Why are my boiled potatoes mushy on the outside but still hard inside?

This is almost always caused by starting in already-boiling water. The outside cooks too fast before the heat has time to penetrate the center. Start in cold water and the temperature rises evenly throughout the potato.

What is the best potato for boiling to make mashed potatoes?

Russet potatoes are the classic choice for mashing because their high starch content produces a fluffy, light mash. Yukon Golds are an excellent alternative – they produce a creamier, more buttery mash and are harder to overcook. Avoid waxy red potatoes for mashing; they produce a dense, gluey texture.

What potato is best for potato salad?

Waxy potatoes – red bliss, fingerling, or new potatoes – are the best choice for potato salad because they hold their shape after boiling rather than falling apart. Russets can be used but require careful monitoring since they soften quickly and can turn mushy in a salad.

Do I need to peel potatoes before boiling them?

No – and often it is better not to. Boiling with the skin on keeps the potato from absorbing excess water and losing starch. For potato salad, boil skin-on and peel (or leave the skin) after cooking. For mashed potatoes, the skin slides off easily after boiling if you prefer a peel-free mash.

How long does it take to boil cubed potatoes?

1-inch cubes take 12 to 15 minutes from when the water comes to a simmer. Smaller half-inch cubes (good for soups and chowders) take 8 to 10 minutes. Always test with a fork – timing varies slightly based on starch content and exact cube size.

Can I boil potatoes the day before?

Yes. Boiled potatoes keep well in the refrigerator for up to 4 days. They firm up as they cool due to starch changes, so for mashed potatoes you will need to add a splash of warm cream when reheating to restore the texture. For potato salad, cooked potatoes can be refrigerated and dressed the next day.

Why do my mashed potatoes turn out gluey?

Overworking the potatoes after they are cooked is the main culprit – the more you mash or mix, the more starch is released and the gluier the texture becomes. Use a potato ricer or masher rather than a food processor or blender. Also make sure you are draining thoroughly and steaming dry before mashing.

Does it matter whether I cover the pot while boiling potatoes?

A lid speeds up the time to reach a boil but is not necessary once the water is simmering. Once your potatoes are in simmering water, you can leave the lid slightly ajar or off entirely. Covering tightly can cause the pot to boil over.

How do I boil small new potatoes whole?

Place them in cold salted water, bring to a simmer, and cook for 15 minutes. Their thin skins mean they cook faster than standard potatoes of the same size. Test with a knife at the 12-minute mark – you want the knife to go in easily but the potato to hold together. Drain and serve warm tossed with butter and fresh herbs.

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Happy cooking,
Julia