My balance looks wrong

First, make sure the wallet is Synchronized (status bar). A balance is only complete once every block has been scanned. Expecting a payment that isn’t there? See A payment hasn’t arrived.

Monero

• Part of it is unconfirmed after you sent a payment: your change is locked for 10 blocks, about 20 minutes. See Balance.
• Frozen coins don’t count. Check View › Coins: frozen outputs show in blue. Thaw them to count them again.
• Another account: each account has its own balance. Check the account switcher.
• Wallet › Advanced › Rescan spent asks the node again which outputs are spent.
• Restored from a seed with a restore height too high: older payments are missed. Restore again with an earlier date.
• A view-only wallet doesn’t see what you spent, see View-only wallets.

If nothing helps, restore the wallet from its seed into a new file. It rebuilds everything from the blockchain.

Bitcoin and Litecoin

• Check the right wallet is selected: each has its own balance.
• Coins on older address types of your seed (1…, 3…, L…, M…) aren’t shown: Biscuit uses native SegWit.
• Payments far beyond your used addresses: see the last step of A payment hasn’t arrived.