Forecast SaaS metrics without Excel — a 6–24 month projection
Forecast SaaS metrics without Excel — a 6–24 month projection
"When do we hit $1M ARR?" — the question asked at every board meeting. Usually the answer lives in an Excel sheet with a compound-interest formula that no one but its author understands.
A growth forecast is one formula, and it doesn't need Excel. All you need is the current value and the monthly rate.
The forecast math in one line
> MRR in N months = MRR_now × (1 + rate)^N
This is compound interest. That's exactly why a small difference in the monthly rate becomes a huge difference over a year:
| MoM rate | After 12 mo | After 24 mo | ||
|---|---|---|---|---|
| 5% | ×1.80 | ×3.23 | ||
| 10% | ×3.14 | ×9.85 | ||
| 15% | ×5.35 | ×28.6 | ||
| 20% | ×8.92 | ×79.5 |
How to build a forecast in a minute
1. Open MRR Growth Rate.
2. Enter the start and end MRR for a month — the calculator shows your MoM rate.
3. Look at the projection: where revenue lands in 6–24 months at that rate.
4. Move the rate and watch the curve change — these are What-If scenarios with not a single formula.
Tip: use a trailing 3-month average rate, not the last month — one big contract distorts the forecast.
Check against T2D3 — is the path to $100M realistic?
T2D3 (Triple, Triple, Double, Double, Double) is the benchmark trajectory from $1M → $100M ARR in 5 years:
| Year | ARR | YoY | ≈ MoM | ||
|---|---|---|---|---|---|
| 1 | $3M | 3× | ~9.5% | ||
| 2 | $9M | 3× | ~9.5% | ||
| 3 | $18M | 2× | ~6% | ||
| 4 | $36M | 2× | ~6% | ||
| 5 | $72M | 2× | ~6% |
Where a forecast is MISLEADING
1. The rate isn't constant — at scale the curve always slows (you can't hold 20% MoM at $100M ARR). A fixed-rate forecast is optimistic over a long horizon.
2. Small base — $5k→$7k = 40% MoM, but it isn't repeatable.
3. Seasonality — Q4 e-commerce ≠ Q1 SaaS; normalize.
4. Churn isn't in a pure growth forecast — high MoM with high churn = fragile growth (cross-check with Quick Ratio).
So a forecast isn't a promise but a range of scenarios: conservative (−churn effect), base (trailing average) and optimistic.
Bottom line
Forecasting SaaS metrics doesn't need Excel — it's one compound-interest formula the calculator builds for you over 6–24 months. Set the current value and trailing rate, check the curve against T2D3, move the rate for scenarios — and the board meeting gets an honest number instead of "we hope".
Calculate your MRR Growth and projection below — the built-in calculator shows the rate, the projection and a stage benchmark.
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Further resources
- /en/mrrGrowthRate — MRR Growth Rate + projection
- /en/mrr — MRR · /en/arr — ARR (MRR × 12)
- /en/quickRatio — Quick Ratio (growth durability)
- /en/blog/mrr-growth-rate-yc — why YC looks for 5-7% MoM