What is flux analysis?

Flux analysis compares each account between two periods, such as this month against last month or this quarter against the same quarter last year, and flags the changes above a threshold for explanation. It is how accountants and auditors spot errors and unusual movements, and it complements budget vs actual, which compares against plan.

How much variance is worth explaining?

Set a threshold in both percentage and dollar terms, for example 10% and $5,000, and explain anything that breaches either. Percentage alone flags noise on small accounts; dollars alone misses large swings on small lines that matter. The thresholds should be agreed with whoever reads the report.

Do I need FP&A software or is a spreadsheet enough?

A spreadsheet is enough while one person owns the budget and actuals are pasted in monthly. Software earns its cost when several people contribute to the plan, when actuals need to update without manual exports, or when the same variance commentary is rewritten every month.

Buyer's guide

Budget vs actual software for QuickBooks Online, compared

Budget vs actual software for QuickBooks Online pulls your actuals from QuickBooks, lines them up against a budget or forecast, and shows the variance by account, department or period, so you can explain what moved and why. QuickBooks Online can hold a budget and run a basic budget-vs-actuals report, but it does not do driver-based planning, rolling forecasts or written variance commentary.

The tools below range from inexpensive planning apps for a single small business to full FP&A platforms sold on annual contracts. The right one depends mostly on whether you need to build the plan in the tool or only to compare against one.

6 tools compared, listed alphabetically, not ranked. VarianceDesk is our own app; we have tried to describe it as plainly as the others. Pricing and features checked October 2026; confirm with the vendor.

How to choose

Do you need to build the budget in the tool (drivers, headcount, departments), or only compare actuals against a budget you already have?
How current the actuals are: a nightly or on-demand sync from QuickBooks Online, or a monthly import.
Variance explanation: does it identify the largest drivers and help you write the commentary, or just show the numbers?
Spreadsheet fit: some tools are built around Excel or Google Sheets; others replace the spreadsheet.
Contract and price: annual FP&A contracts start in the thousands; lighter tools are monthly.

Comparison at a glance

Tool	Best for	QuickBooks Online	Starting price	Notable limit
Cube	Mid-market finance teams who want to stay in spreadsheets	Yes (QuickBooks connector)	Pricing on request	Sales-led; vendor cites a 2–4 week setup
Datarails	Excel-heavy finance teams at small and mid-size companies	Yes (QuickBooks Online sync by entity)	Pricing on request	Entry plan allows 2 users and 1 integration
Fathom	Advisors producing budget reports for clients	Yes (QuickBooks Online and Desktop)	Tiered by number of companies; see Fathom's pricing page	Budgets and custom KPIs require Pro
Jirav	Growing companies with a finance lead	Yes (trial balance and chart of accounts import)	$10,000/yr billed annually (Starter, businesses); firm plans from $50/mo	Imports monthly trial balances; one accounting system per company
LivePlan	Startups and small single-entity businesses	Yes (QuickBooks Online and Xero)	$40/mo billed monthly, or $30/mo billed annually (Premium, the plan with QuickBooks sync)	QuickBooks sync and dashboards need Premium; one active company
VarianceDeskOur app	Owners and controllers explaining monthly variances to a board	Yes, read-only connection	$49/mo per app; 14-day free trial	Compares against a budget; it is not a planning or modeling tool

Pricing and features checked October 2026; confirm with the vendor.

The options in more detail

Cube

Cube is FP&A software that works inside Excel and Google Sheets, covering annual budgeting, scenario planning and variance analysis on data pulled from the ledger. It suits a finance team that already lives in spreadsheets and wants a central data layer under them. All tiers are quoted, so expect a sales process.

Datarails

Datarails is another Excel-based FP&A platform: it consolidates data from QuickBooks Online and other systems and supports reporting, planning and budget vs actual from Excel. Plans are differentiated by users and number of integrations, and every tier is quoted.

Fathom

Fathom's Pro plan includes budgets, scenarios, custom KPIs and budget analysis in polished management reports. It is popular with accounting and fractional-CFO firms. Pro is priced per company, with multi-company bundles for firms.

Jirav

Jirav is a driver-based planning platform with departmental and workforce planning, rolling forecasts, three-statement projections and budget vs actual. It is the most complete planning tool here for a single company, and the business pricing reflects that. Accounting and CFO firms can use it on much lower per-month plans.

LivePlan

LivePlan builds a plan and forecast, then tracks actuals from QuickBooks Online against it in budget-vs-actual dashboards. QuickBooks sync and the dashboards are on the Premium plan. It is inexpensive and approachable. It is not built for department-level budgets or detailed variance commentary.

VarianceDeskOur app

VarianceDesk is our app, and it is generally available. It reads QuickBooks Online, compares actuals against your budget, ranks the largest favorable and unfavorable drivers, runs period-over-period flux, and drafts plain-language commentary you edit before it goes in the board pack. It does not build the budget itself: if you need driver-based planning or headcount models, Jirav, Cube or Datarails do that and VarianceDesk does not.

Start a 14-day free trial →How VarianceDesk works →

Which one fits

If you already have a budget and the monthly pain is explaining variances, VarianceDesk or LivePlan are the lightest options; VarianceDesk goes further on variance drivers and commentary, LivePlan on building the plan. If you need to build a driver-based plan with departments and headcount, Jirav is the most complete for a single company. Teams committed to Excel or Google Sheets should compare Cube and Datarails. If an advisor prepares your reporting, Fathom is likely what they use.

Common questions

Can QuickBooks Online do budget vs actual?: Yes, at a basic level. QuickBooks Online lets you enter a budget and run a budget-vs-actuals report on supported plans. It does not do driver-based planning, rolling forecasts, or explain why a line moved, which is why teams add a planning or variance tool once the board wants commentary.
What is flux analysis?: Flux analysis compares each account between two periods, such as this month against last month or this quarter against the same quarter last year, and flags the changes above a threshold for explanation. It is how accountants and auditors spot errors and unusual movements, and it complements budget vs actual, which compares against plan.
How much variance is worth explaining?: Set a threshold in both percentage and dollar terms, for example 10% and $5,000, and explain anything that breaches either. Percentage alone flags noise on small accounts; dollars alone misses large swings on small lines that matter. The thresholds should be agreed with whoever reads the report.
Do I need FP&A software or is a spreadsheet enough?: A spreadsheet is enough while one person owns the budget and actuals are pasted in monthly. Software earns its cost when several people contribute to the plan, when actuals need to update without manual exports, or when the same variance commentary is rewritten every month.