ARR Bridge Calculator
Quarterly ARR waterfall · NRR/GRR · Magic Number · Burn Multiple · Rule of 78
Quarter Inputs
| Quarter | New ARR | Expansion | Contraction | Churn | Net New |
|---|---|---|---|---|---|
| Q1 2024 ✏ | $ | $ | $ | $ | +$250k |
| Q2 2024 ✏ | $ | $ | $ | $ | +$340k |
| Q3 2024 ✏ | $ | $ | $ | $ | +$430k |
| Q4 2024 ✏ | $ | $ | $ | $ | +$525k |
| Total | $1.2M | $810k | $190k | $275k | +$1.5M |
ARR Bridge Waterfall
Avg NRR
102.9%
Retention positive
Expansion Share
52%
$810k from existing
Gross ARR Churn
4.1%/qtr
$275k lost to cancellations
Next Milestone
$5.0M
~3 qtrs at current rate
Magic Number
5.36
EliteCAC Payback
9 mo
Best in classARR / FTE
$121k
StrongBurn Multiple
0.92×
ExceptionalARR Efficiency Scorecard
NRR & GRR Trend
Net Revenue Retention vs Gross Revenue Retention. Reference bands: 80% · 100% · 110% · 120%
ARR Composition
Retained base · Expansion · New logos stacked
New ARR Attribution
Channel mix: Outbound · Inbound · PLG · Partner
Ending ARR Anatomy
Benchmark Comparison
158% NRR: existing customers alone grow ARR 58% with zero new logos.
Multi-product expansion kept NRR 130%+ as customers adopted more modules.
Seat + product expansion across 150k+ SMB. Predictable 8–10pp expansion/year.
Magic Number above 1 signals repeatable go-to-market.
Series A: still finding GTM motion. NRR improves as first cohorts mature.
Low S&M per ARR dollar. Burn Multiple < 1 is rare and exceptional.
Magic Number 5.4 — under-resourced
You have efficient S&M (pays back in <12 months) but slow ARR growth. This usually means S&M is efficient but under-resourced.
→ You can likely 2× S&M spend and maintain unit economics. Projected impact: +$1.1M ARR per quarter if spend doubles.
What is an ARR Bridge?
An ARR bridge — also called an ARR waterfall chart or annual recurring revenue bridge — shows exactly how your recurring revenue changed between two periods by decomposing it into four movements: new logos, expansion from existing customers, contraction (downgrades), and churn (cancellations). The formula is: Ending ARR = Beginning ARR + New ARR + Expansion ARR − Contraction ARR − Churned ARR. This quarterly ARR breakdown is the universal language of SaaS board reporting — every investor, CFO, and VP Sales reads it the same way.
The power of the ARR movements calculator format is that it separates the "what" (how much ARR changed) from the "why" (which motions drove it). Two companies can end the same quarter at identical ARR levels — but one got there by churning half their base and replacing it with new logos (high-risk, low NRR), while the other grew primarily through expansion (low CAC, high NRR, durable). The bridge makes that difference visible instantly.
New ARR vs. Expansion ARR: Why the Split Matters
New ARR comes from customers who didn't exist in your base last period — it requires full sales and marketing investment: demand generation, SDRs, AEs, onboarding. Expansion ARR comes from existing customers upgrading, adding seats, buying new product lines, or exceeding usage thresholds — typically at 3–5× lower CAC because the customer already trusts you. A healthy SaaS business progressively shifts its growth mix toward expansion as it matures, which is why Net Revenue Retention (NRR) above 100% is the single most powerful compounding advantage in SaaS.
The SaaS board deck ARR chart should always show the new/expansion split explicitly. A business generating 80% of net new ARR from expansion has a fundamentally different risk profile than one relying entirely on new logos. The former can grow ARR even in a sales hiring freeze; the latter cannot. Tracking this ratio every quarter is essential for planning headcount, budget allocation, and fundraising narrative.
How to Calculate Magic Number from Your ARR Bridge
The SaaS Magic Number measures the efficiency of your go-to-market investment. Formula: Magic Number = (Net New ARR × 4) ÷ Prior Quarter S&M Spend. Multiplying by 4 annualizes the quarterly ARR, making it comparable to annual S&M spend. You use the prior quarter's spend because there is a natural 30–90 day lag between marketing spend, pipeline generation, and closed ARR.
Benchmarks: below 0.5 is inefficient (spend outpaces ARR generation — audit CAC by channel before scaling); 0.5–1.0 is developing (below payback threshold — optimize highest-CAC channels first); 1.0–1.5 is efficient (S&M pays back in under 12 months — safe to scale); 1.5–2.5 is high efficiency (exceptional unit economics — consider doubling spend on top channels); above 2.5 is elite (top-decile, product-market fit is strong). This SaaS magic number calculator pairs the metric with your actual ARR bridge data so you can see efficiency trend alongside absolute ARR growth.
The Rule of 78: Why Q1 Logos Are Worth 4× Q4 Logos
The Rule of 78 is one of the most underused insights in SaaS planning. If you add a fixed amount of new ARR every month, a January (Q1) logo contributes 12 months of ARR to your year-end total, while a December (Q4) logo only contributes 1 month. Sum all contributions across a year: 12+11+10+…+1 = 78 months — hence the name. This means a Q1 new logo is worth exactly 4× a Q4 new logo to current-year ARR.
The practical implication: front-loading your annual sales plan has a disproportionate impact on year-end ARR. Missing Q1 quota by 30% cannot be recovered by accelerating Q3–Q4, because those late logos simply don't accumulate enough months to compensate. This is why experienced SaaS CFOs focus intensely on Q1 pipeline coverage — and why the Rule of 78 Planner in this tool shows you exactly how much monthly new ARR you need to hit any target ARR by year-end.
How VCs Read Your ARR Bridge in 60 Seconds
Experienced investors have a pattern-recognition scan they run on every ARR bridge. They look for three signals: (1) Is NRR above 100%? This proves product-market fit in existing accounts — your current customers find enough value to pay you more over time. (2) Is the new logo line growing QoQ? Accelerating new ARR proves the go-to-market motion is repeatable and scalable, not dependent on a handful of large deals. (3) Is logo churn stable or declining? Deteriorating churn is a leading indicator of product or market problems — and growth will amplify the damage, not fix it.
At Series B and beyond, investors also look at efficiency: Magic Number above 1, Burn Multiple below 2, CAC Payback under 24 months. A beautiful ARR growth chart with a Magic Number of 0.3 raises immediate concerns about scalability. The ARR bridge surfaces the full picture — growth rate, retention quality, and capital efficiency — in a single view that takes 60 seconds to read.
ARR Benchmarks by Stage: Series A, B, and Scale
Series A: 2–3× ARR YoY (100%+ growth), NRR 100–110% as first cohorts mature, Magic Number often below 1 while still finding GTM fit, Burn Multiple 2–3× is acceptable given the investment in discovery. Series B: 80–100% ARR growth, NRR 110–120%, Magic Number above 1.0 signals a repeatable go-to-market engine, Burn Multiple targeting below 2. Series C / Scale: 40–80% ARR growth on a larger base, NRR 115–130%+ as the expansion flywheel matures, Burn Multiple below 1.5, CAC Payback under 18 months.
Public benchmarks: Snowflake hit 158% NRR at IPO — existing customers alone grew ARR 58% annually with zero new logos, powered by consumption-based pricing. Datadog sustained 130%+ NRR through multi-product expansion across APM, logs, and security modules. HubSpot at scale operates at 108% NRR with 33% ARR growth across 150k+ SMB customers — proof that durable, if slower, expansion compounds meaningfully at scale.
ARR Bridge vs. MRR Waterfall: When to Use Each
The MRR waterfall is used for monthly subscription businesses with high transaction volume and fast feedback loops — common in PLG, developer tools, and consumer SaaS where deals close daily and churn signals are visible within 30 days. Monthly granularity matches the operational cadence: marketing campaigns, product sprints, and cohort analysis all run monthly.
The ARR bridge is the standard for enterprise and mid-market SaaS where deals are quarterly or annual contracts, negotiated by sales teams, and reviewed at the board level. Quarterly aggregation matches the cadence of board reporting, pipeline reviews, quota periods, and annual planning. A monthly MRR view of an enterprise business introduces noise (invoice timing, annual renewals landing in one month) that a quarterly ARR breakdown smooths out. This tool uses quarterly periods to align with standard SaaS board deck reporting conventions.
Last reviewed: March 2026