Budget planning for a small business is not about picking a round number and hoping it works. It is about working backwards from what a customer is worth, how many clicks you can afford, and how long you can keep testing before you judge the result. This guide shows that calculation with honest, everyday numbers.
Start with the value of a conversion
Suppose a plumbing job is worth $250 in revenue and about $120 in profit after parts, labor, and overhead. If 1 in 4 enquiries becomes a job, each enquiry is worth about $30 in profit. That means a cost per lead above $30 is hard to sustain, even if the campaign looks busy. If you do not know these numbers yet, estimate conservatively and track every lead for a month before raising the budget.
Turn the monthly budget into clicks and leads
Take a $900 monthly budget and a $2.00 average CPC. That buys 450 clicks. At a 4% conversion rate, that is 18 leads, at $50 per lead. If that CPA is too high for your profit, you have three honest choices: improve the landing page and conversion rate, choose cheaper, more specific keywords, or accept that you need a larger budget or a different channel for now. The Budget Calculator lets you test these combinations before spending.
A practical monthly plan
- Weeks 1 to 2: launch with tight keywords, one clear offer, and conversion tracking checked.
- Weeks 3 to 4: pause keywords with many clicks and no leads, add negatives, and fix the weakest landing page.
- Month 2: shift budget toward the ad groups with the best cost per lead, not the most clicks.
- Month 3: only then consider raising the budget by 20 to 30%, if leads are profitable.
Keep a small reserve for testing, separate from your main campaign, so a test does not eat the budget that brings in leads. Also set a daily cap you can afford every day of the month, because Google can spend more on a strong day and less on a quiet day within the monthly limit. For related help, read bidding strategies and common beginner mistakes, and check profit in the ROAS and Profit Calculator.
[…] budgets are usually clearer. You can always move budget after two or three weeks of data. Read the budget planning guide and the keyword research guide before you set those numbers, and use the Budget Calculator to […]
[…] budget you can afford to lose for learning, and treat the first month as research, not profit. The budget planning guide and the Budget Calculator will help you turn a monthly budget into a daily budget and an expected […]