What helped profit and what hurt it?
Profit went up $2,400 or down $3,100. Great, but why? Here's how to trace the change back to the specific line items that caused it.
The short answer
To find what helped and hurt profit, run a P&L comparison report (this month vs. last month) and look at the dollar change for each line item. Revenue increases help profit. Expense increases hurt it. The largest changes are your answers. Below, we walk you through this in QuickBooks and Xero.
Why the profit number alone is not enough to act on
Your net income dropped from $10,200 last month to $6,200 this month. A $4,000 decline. That is the symptom. The diagnosis requires knowing which line items caused it.
Maybe revenue was up $5,000, but payroll increased $6,000 (you hired someone) and ad spend jumped $3,000 (you doubled your Google budget). The revenue growth was good. The payroll increase was planned. The ad spend increase is the one to investigate because it was not budgeted and may not be producing results.
Without this breakdown, you are left with “profit went down” and no idea where to focus. With it, you have a specific list of changes ranked by impact, and you can decide which ones to accept and which ones to address.
How to think about profit drivers and drags
Every P&L line item either helped or hurt your profit compared to the prior period. Here is how to categorize them:
- Revenue increase: Helped profit. More money came in. But check whether the increase came with proportional cost increases (e.g. you sold more but materials cost rose too).
- Revenue decrease: Hurt profit. Less money came in. Investigate whether it was fewer customers, lower prices, or delayed collections.
- Expense increase: Hurt profit. More money went out. But not all increases are bad. Hiring a salesperson is an investment. An unexpected equipment repair is not.
- Expense decrease: Helped profit. Less money went out. Verify this is a real savings, not just a timing difference (an annual payment that hit last month but not this month).
How to find profit drivers in QuickBooks Online (5 steps)
- 1Open the Profit and Loss Comparison report
From the left sidebar, click Reports. Search for “Profit and Loss Comparison.” This report automatically compares two periods. Set it to this month vs. last month.
- 2Look at the “$ Change” column
QuickBooks shows the dollar change and percentage change for each line item. Focus on the dollar change. Sort mentally by the largest absolute values.
- 3Identify the top 3-5 changes by dollar impact
Look at revenue changes first (did you make more or less?), then scan expenses for the largest increases or decreases. These are your profit drivers and drags.
- 4Click into each changed category
Click the number to see individual transactions. This tells you whether a $3,000 ad spend increase was from raising your Google budget, a one-time event sponsorship, or agency fee increases.
- 5Verify that Net Income change matches your sum
Add up the revenue changes (positive = helped) and expense changes (positive = hurt). The net should equal your Net Income change. If it does not, look for other income or other expense items you may have missed.
Total time: about 8-10 minutes. The comparison report does the math. Your job is to identify the biggest changes and investigate the ones that were not intentional.
How to find profit drivers in Xero (4 steps)
- 1Go to Accounting → Reports → Profit and Loss
Set the date range to the current month. Select “Compare with: Previous Period.” Click Update.
- 2Calculate the dollar change for each line
Xero shows both periods side by side but does not automatically calculate the variance. Subtract last month's figure from this month's for each significant line item. Focus on items with changes greater than $500.
- 3Click into the largest changes
Click any account number to see the transactions behind it. This tells you the “why” behind each change.
- 4Export to spreadsheet for a sorted view
Click Export to download both periods. Add a column for the difference and sort by largest absolute change. This gives you a ranked list of profit drivers and drags.
Total time: about 10-12 minutes. Xero requires more manual calculation than QuickBooks for variance analysis. The spreadsheet export helps.
What it takes to analyze profit drivers every month
- 8-12 minutes per month to run the comparison, identify the top changes, and investigate the unexpected ones.
- Judgment about what is intentional. A payroll increase because you hired someone is planned. An ad spend increase you did not authorize is not. You need context beyond the numbers to tell the difference.
- Cross-referencing with non-accounting data. Ad spend went up $3,000. Did conversions go up too? Revenue from one client dropped $8,000. Did they churn or just delay? The P&L shows the financial impact but not the business context.
Or see exactly what helped and hurt profit, automatically
Bottomline compares every P&L line item month over month and ranks them by impact on profit. No manual subtraction, no spreadsheet exports:
Bottomline also adds the context your P&L cannot provide. If ad spend went up $3,200, it shows whether conversions and new customers also went up. If revenue from a client dropped, it checks your CRM for pipeline activity. The financial data gets the business context it needs to be actionable.