A Google Ads budget is a spending cap, not a guarantee. Google may overspend on individual days but balances out across your set period.

• Daily budgets reset every 24 hours. Google can spend up to 2× your set daily budget on a single day but won’t exceed your monthly cap. Best for evergreen campaigns, consistent pacing, and accounts tied to monthly finance cycles;
• Lifetime budgets set one fixed cap across the entire campaign period. Spend is distributed dynamically, giving Google flexibility to push harder on peak days. Best for promotions, seasonal pushes, or grant-funded campaigns;
• Use daily budgets when you want tight, ongoing control - ideal for search, shopping, or always-on lead generation;
• Use lifetime budgets when campaigns are time-bound, such as a 14-day product launch or Black Friday sale;
• Avoid sudden, drastic budget changes (like doubling overnight). Instead, adjust gradually (10–20% at a time) to avoid disrupting the algorithm;

Daily budgets give you control, lifetime budgets give you pacing flexibility. Choose based on whether your campaign is evergreen or time-boxed.