To calculate SROI as new evidence arrives, connect each outcome to its source record, apply documented financial proxies and contribution adjustments, and divide the present value of adjusted outcomes by the investment. Keep the scope and calculation rules versioned. When a record changes, review its effect before releasing an updated ratio. Program leads, evaluators and funders can use this method to maintain a calculation they can explain, rather than rebuild it from a fresh spreadsheet export.
By Sopact Academy · Updated September 12, 2026. The worked figures are illustrative.
Maintain a calculation your team can check
Bring: one outcome from your exit-measurement report, its source records and the associated program costs.
Leave with: a reviewed calculation version, a checked change and a log that distinguishes a working estimate from an approved reporting version.
This is an optional exercise for maintaining an existing valuation model. For a full introductory walkthrough and calculator, use the SROI framework and calculator. Here, the task is keeping an existing calculation reliable as evidence changes.
“Live” describes how the evidence is maintained. It does not mean every new response is a verified outcome, every change should alter the published ratio, or a higher ratio proves the program improved.
- Define the decision, participants and reporting period.
- Connect outcome evidence to the same people over time.
- Separate observed change from the monetary value assigned to it.
- Apply and document the contribution adjustments.
- Calculate a worked ratio and test its sensitivity.
- Review new evidence, then save a dated reporting version.
What makes a live SROI calculation trustworthy?
A trustworthy calculation lets a reviewer follow the ratio back to the outcomes, assumptions and records behind it. A dashboard can refresh quickly and still carry weak evidence.
Keep three things distinct: what you observed, how you valued it, and how much contribution you claimed. For example, a participant’s reported wage increase is an observation. Annualizing that increase requires working-hours and duration assumptions. Estimating the share attributable to the program requires additional evidence. Store each separately.
The broader method is described in Social Value International’s Guide to SROI. This lesson focuses on keeping the calculation current and reviewable. For the full introduction, see the SROI framework and calculator.
Define the scope before connecting the data
Write down whose changes you will value, over which period, against which investment. Use that same scope whenever you refresh the result.
For a workforce program, specify whether the analysis covers one intake cohort or all participants in a year. Define employment, retention and earnings consistently. Include material negative outcomes and people who leave the program; excluding them can make the result look better without changing the work.
- Decision: What will this evidence help the team decide?
- Population: Who is included, and who is missing?
- Period: When do costs and outcomes count?
- Investment: Which inputs belong in the denominator?
- Evidence cutoff: Which records were available for this version?
Build a value map that separates evidence from estimates
Give each outcome a source, an observation date and a valuation basis. Label borrowed estimates so a reader can distinguish measured change from assumptions about its monetary value.
Use a stable participant ID to connect intake, services, case notes and follow-up. A shared identifier links records; it does not establish that the program caused the change. Keep the relevant consent, access permissions and retention rules with the data workflow.
| Record component | What to store | Example or rule |
|---|---|---|
| Observed outcome | Baseline and follow-up, dates, units and source | Hourly wage before and after the program; distinguish self-report from verified payroll. |
| Monetary value | Proxy or valuation method, source, geography and year | If annualizing wage gains, state hours worked and the benefit period. |
| Contribution | Deadweight, attribution and displacement assumptions | Record each adjustment separately, with the evidence and uncertainty behind it. |
| Duration | Benefit period, drop-off and discount rate | Do not assume a year-one benefit continues indefinitely. |
| Review status | Complete, awaiting evidence, not applicable or disputed | A missing follow-up is an evidence gap, not a confirmed zero outcome. |
Where an outcome matters but no defensible monetary proxy exists, report it in its own units and explain the exclusion from the ratio. Do not invent a value to complete the table. Use the value-map walkthrough and financial-proxy guide for the underlying decisions.
Apply the adjustments without hiding uncertainty
Estimate how much outcome value should be credited to the work, then test how different reasonable assumptions affect the result. Participant feedback can inform these estimates, but a response such as “mostly because of the program” does not establish a universal numerical attribution factor.
| Adjustment | Question it answers | What to make explicit |
|---|---|---|
| Deadweight | What would have happened anyway? | The comparison, benchmark or other basis for the estimate. |
| Attribution | How much did others contribute? | Other services, employers, family support or contextual influences. |
| Displacement | Did a gain replace or reduce value elsewhere? | Who else may have experienced a loss or foregone benefit. |
| Drop-off | How do benefits fade in later years? | Evidence or assumptions about persistence over time. |
| Discounting | What are future benefits worth in present terms? | The rate, timing convention and reason for choosing them. |
Check for double counting. A wage gain, a tax contribution and a benefit saving may overlap depending on the stakeholder perspective and scope. They should not automatically be added together. See deadweight and attribution for a closer treatment.
Watch: What an SROI ratio really means
4 minutes 13 seconds · SROI explainer with a worked 3:1 example and the assumptions behind it.
▶ Play the SROI explainer
Calculate the ratio with a transparent worked example
SROI ratio = present value of adjusted outcomes ÷ value of inputs. A 3:1 result means an estimated $3 of social value per $1 invested within the stated scope. It is not $3 in cash returned or proof of causation.
The following example is hypothetical and matches the worked example in the accompanying video. For this simplified arithmetic exercise, costs and benefits are expressed at a common valuation date, with one outcome and no displacement. Timing adjustments are omitted here; a real study must account for when costs and benefits occur. A complete study must justify those assumptions.
| Calculation | Working | Result |
|---|---|---|
| Gross outcome value | 100 people × $2,000 per outcome | $200,000 |
| Remove deadweight | 20% of $200,000 is excluded | $160,000 remains |
| Remove others’ contribution | 25% of the remaining $160,000 is excluded | $120,000 remains |
| Divide by investment | $120,000 ÷ $40,000 | 3:1 estimated SROI |
Now change one assumption. If deadweight is 40% rather than 20%, the adjusted value becomes $200,000 × 0.60 × 0.75 = $90,000. With the same $40,000 investment, the ratio is 2.25:1. The modeled assumption changed; this sensitivity test adds no new outcome evidence and does not show the program became better or worse.
For a multiyear model, calculate each period’s benefits, apply the relevant persistence and contribution assumptions, and discount future amounts consistently. Show the base case and sensitivity range beside the result. The ratio walkthrough explains the calculation in more detail.
What should happen when a new record arrives?
A new record should update the evidence trail first. Recalculate affected values after the identity, units, dates and review status pass your checks. Keep the prior reporting version available.
| Incoming information | First check | Action |
|---|---|---|
| A follow-up wage response | Correct participant, date, currency and hourly or annual units? | Update the observed outcome; flag discrepancies for review. |
| A follow-up is overdue | Is the outcome unknown or explicitly reported as unchanged? | Show the coverage gap. Do not label missing evidence as verified failure or success. |
| A revised financial proxy | Does its population, geography and year fit the study? | Test the effect in a new model version before adopting it. |
| A mentor note challenges an outcome | Does it contradict a claim used in the calculation? | Route the discrepancy to a reviewer and retain both sources. |
| A reviewer approves a correction | Are the rationale and affected results recorded? | Save the updated version with the evidence cutoff and change log. |
Track evidence coverage beside SROI: how many follow-ups are due, how many arrived, and which outcomes remain unresolved. If you produce a provisional estimate, label it and explain how missing information is treated. Avoid interpreting a ratio that rises as responses arrive as proof of better performance.
Keep cost per outcome separate. It answers a different question. If your outcome is employment retained for 90 days, divide the relevant program cost by the number of people meeting that definition. Report the cohort, period and evidence coverage; do not substitute enrollment or completion for retention.
Keep a change log beside the ratio
This fictional log separates a changed assumption from corrected evidence. Versions B and C are independent changes from A, not a sequence to combine.
| Version | Change | Working | Review |
|---|---|---|---|
| A · base case | 100 outcomes, $2,000 valuation, 20% deadweight, 25% attribution adjustment | 100 × $2,000 × 0.80 × 0.75 ÷ $40,000 = 3:1 | Keep approved evidence and assumptions |
| B · sensitivity | Test deadweight at 40%; other inputs unchanged | $200,000 × 0.60 × 0.75 ÷ $40,000 = 2.25:1 | Scenario until the assumption is justified and approved |
| C · correction | Two outcome records were duplicates; retain base-case assumptions | 98 × $2,000 × 0.80 × 0.75 ÷ $40,000 = 2.94:1 | Review the correction before issuing a revised report |
Each version needs a source, reviewer and decision. A movement in the ratio does not by itself establish that the program became more or less effective.
How can Sopact support the workflow?
You can build the initial value map and calculation in a spreadsheet. The recurring challenge is maintaining connections across forms, documents, case notes and follow-up records while keeping definitions and access consistent.
In Sopact, organize those sources around the participant, program and observation date. Configure the analysis around your approved outcome definitions, proxies and adjustments. Use source-linked review to investigate gaps and compare calculation versions. Confirm the configuration against a manually checked sample before relying on it for reporting.
AI can help extract candidate evidence, surface conflicting records and explain a calculation. Reviewers still decide whether an outcome is supported, a proxy is appropriate and a contribution claim is defensible. Keep sensitive participant details available only to authorized roles.
Try this review prompt with a value map and calculation you can inspect:
Review this SROI model using only the supplied records, scope, proxies and adjustment rules. For each outcome, show the observation, source, monetary value, contribution adjustments and review status. Flag missing evidence, inconsistent units, overlapping benefits and assumptions without a cited basis. Reproduce the base-case arithmetic and test the supplied sensitivity ranges. Do not invent missing values or infer causation from a linked record. List the decisions a human reviewer must resolve before publication.
What should you check before sharing the result?
Share the ratio with the information needed to question it. A single number without scope, sources or assumptions is difficult to use responsibly.
- Confirm the population, period, investment and evidence cutoff.
- Trace material outcomes to their original records.
- Separate observed change from borrowed valuation assumptions.
- Review negative outcomes, missing voices and double counting.
- Document all contribution and duration adjustments.
- Show sensitivity results and unresolved evidence gaps.
- Record who reviewed the model and which decisions changed.
Start with one outcome this week. Connect its baseline and follow-up, identify a defensible valuation basis, and reproduce the calculation by hand. Only then extend the model to additional outcomes or recurring updates.
What should you test in an SROI calculator or tool?
Use the worked example above as an acceptance test. A useful calculator should let you inspect the assumptions and reproduce the result, not only display a ratio.
- Reproduce the base case: enter the same outcome count, value, deadweight, attribution and investment. Confirm the 3:1 result.
- Change one assumption: increase deadweight from 20% to 40% and confirm 2.25:1 while keeping everything else fixed.
- Correct a source record: use the separate duplicate-correction scenario and confirm 2.94:1. Preserve the reason for the correction.
- Trace the inputs: identify the observation, proxy source, period and reviewer behind each value.
- Review the boundaries: show who and what are excluded, how overlapping benefits are handled and which outcomes lack usable evidence.
- Export the reasoning: check whether a colleague can reproduce the calculation from the output without depending on the original analyst.
A spreadsheet may be enough for a small, stable model. When observations arrive repeatedly from different teams, test how the tool handles updates, permissions and version history. No calculator can decide whether a proxy or causal assumption is appropriate simply because a field is filled in.
Keep this course exercise focused on maintaining a calculation. Use the broader SROI guide to review the method and scope before choosing a tool.
Frequently asked questions
Does “live SROI” mean the ratio changes automatically?
It means the underlying evidence and calculation can be maintained as records change. Your workflow should distinguish a working estimate from an approved reporting version. Decide which changes can be processed routinely and which require review, then save the assumptions and evidence cutoff with each released result.
Can missing follow-up responses count as zero?
A missing response means the outcome is unknown. Treating it as zero may be a conservative modeling assumption in a particular analysis, but it is not an observed zero. Explain the choice, report response coverage and test how alternative treatments affect the result. Retain the full population defined in the study scope.
Can participant feedback establish attribution?
Participant accounts help explain what contributed to change. They should be interpreted alongside the study design and other available evidence. Converting “mostly” into a fixed percentage is an assumption requiring justification, not a general SROI rule. Record the reasoning and test a reasonable range rather than presenting the percentage as a measured causal effect.
Is a higher SROI ratio always better?
No. A ratio can rise because of a broader scope, a larger proxy, different duration assumptions or lower estimated deadweight. Compare like-for-like model versions and explain the drivers. Across programs, differences in participants, outcomes and valuation methods can make headline ratios unsuitable for a simple performance ranking.
Can I combine SROI across programs?
Do not add individual ratios. First check whether the scopes, periods, valuations and contribution rules are compatible. Where aggregation is justified, combine the appropriately adjusted outcome values and corresponding inputs, then calculate the aggregate ratio. Use the portfolio SROI guide to examine those conditions.
What should I do if the result cannot be defended yet?
Keep the estimate provisional and show the specific gap: a missing observation, unsuitable proxy, uncertain contribution estimate or calculation error. Assign someone to resolve it. You can still use non-monetized outcome evidence to improve the program while the valuation work continues; a premature ratio is not a prerequisite for learning.
Exercise: explain a changed ratio
Save the 3:1 base case with its evidence cutoff. Create a second version using 40% deadweight; the result becomes 2.25:1. Record which assumption changed, why it changed, who reviewed it and whether the new version is approved for reporting. Keep the original available.
Then consider a different update: ten follow-ups are overdue. Those missing responses do not, by themselves, justify switching deadweight from 20% to 40%. Record the coverage gap and examine its possible effect separately. Your reviewer should be able to tell a new observation, a corrected record and a revised modeling assumption apart.
Continue to the job-training funder-report lesson to present the result with its limitations. For presentation guidance, read How to Write an Impact Report and browse the report examples. A ratio is one part of the explanation, not a substitute for the outcome evidence.