Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Ending ARR
$5,630,000
Net new ARR
$630,000
Period growth rate
12.6%
Gross ARR added
$950,000
Gross ARR lost
$320,000
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter starting arr ($).
- 2Enter new business arr ($).
- 3Enter expansion arr ($).
- 4Enter contraction arr ($).
- 5Enter churned arr ($).
- 6Read your ending arr on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
An ARR bridge (also called a waterfall) decomposes the change in annual recurring revenue between two periods into its component movements: new business, expansion, contraction, and churn. It's the standard board-deck slide because a single ARR growth-rate number hides which lever actually drove the change — the same 20% quarterly growth can come from a thriving expansion motion covering weak new-logo acquisition, or the reverse, and those situations call for completely different management actions. Building the bridge forces internal consistency between your CRM, billing system, and finance reporting, which is why it's also a common source of embarrassing discrepancies during due diligence when the numbers don't reconcile. Track the bridge every quarter, not just at renewal time, so contraction and churn get flagged early rather than discovered in a surprise end-of-quarter reconciliation.
Worked example
Using the values the calculator loads with:
Inputs
- Starting ARR: 5000000 $
- New business ARR: 600000 $
- Expansion ARR: 350000 $
- Contraction ARR: 120000 $
- Churned ARR: 200000 $
Results
- Ending ARR: $5,630,000
- Net new ARR: $630,000
- Period growth rate: 12.6%
- Gross ARR added: $950,000
- Gross ARR lost: $320,000
What each field means
Inputs
- Starting ARR ($)
- The starting arr used in the calculation, measured in $. Starts at 5000000 $ so you have a working example on load.
- New business ARR ($)
- The new business arr used in the calculation, measured in $. Starts at 600000 $ so you have a working example on load.
- Expansion ARR ($)
- The expansion arr used in the calculation, measured in $. Starts at 350000 $ so you have a working example on load.
- Contraction ARR ($)
- The contraction arr used in the calculation, measured in $. Starts at 120000 $ so you have a working example on load.
- Churned ARR ($)
- The churned arr used in the calculation, measured in $. Starts at 200000 $ so you have a working example on load.
Results
- Ending ARR
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Net new ARR
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Period growth rate
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Gross ARR added
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Gross ARR lost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why not just report ending ARR and growth rate?
Two companies can post identical ARR growth with very different underlying health — one from strong new-logo velocity, another from a shrinking base saved by a couple of huge expansions. The bridge exposes which motion is actually working so leadership fixes the right thing instead of the whole go-to-market.
How often should I build an ARR bridge?
Monthly internally for early warning on churn and contraction trends, quarterly for board and investor reporting. Waiting until quarter-end to look at the bridge means you find problems only after the damage is already booked.
What's a common mistake when building one?
Mixing up when a downgrade counts as contraction versus churn (a customer dropping to a much smaller plan without fully canceling), and inconsistent handling of mid-term upgrades. Pick clear definitions once, document them, and apply them identically every period so trends are comparable.
Should reactivated churned customers count as 'new'?
Most finance teams track them as a separate 'reactivation' or 'win-back' line rather than lumping them into new business, since blending them overstates new-logo sales productivity and understates how much churn you're actually recovering from.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Net Revenue Retention (NRR) Calculator
See how much revenue your existing customers generate a year later, expansion included.
Expansion Revenue Rate Calculator
Measure how much of your growth comes from existing customers spending more.
SaaS Quick Ratio Calculator
See how much growth you generate for every dollar of churn and contraction.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). ARR Bridge Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/arr-bridge
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/arr-bridge" target="_blank" rel="noopener">ARR Bridge Calculator — RevenueLab</a> (2026).</p>
Source: [ARR Bridge Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/arr-bridge) (2026).